gnt-instance¶
Name¶
gnt-instance - Ganeti instance administration
Synopsis¶
gnt-instance {command} [arguments...]
DESCRIPTION¶
The gnt-instance command is used for instance administration in the Ganeti system.
COMMANDS¶
Creation/removal/querying¶
ADD¶
Creates a new instance on the specified host. The instance-name argument must be in DNS, but depending on the bridge/routing setup, need not be in the same network as the nodes in the cluster.
The disk option specifies the parameters for the disks of the
instance. The numbering of disks starts at zero, and at least one disk
needs to be passed. For each disk, either the size or the adoption
source needs to be given. The size is interpreted (when no unit is
given) in mebibytes. You can also use one of the suffixes m, g or
t to specify the exact the units used; these suffixes map to
mebibytes, gibibytes and tebibytes. Each disk can also take these
parameters (all optional):
- spindles
- How many spindles (physical disks on the node) the disk should span.
- mode
- The access mode. Either
ro(read-only) or the defaultrw(read-write). - name
- This option specifies a name for the disk, which can be used as a disk identifier. An instance can not have two disks with the same name.
- vg
- The LVM volume group. This works only for LVM and DRBD devices.
- metavg
- This option specifies a different VG for the metadata device. This works only for DRBD devices. If not specified, the default metavg of the node-group (possibly inherited from the cluster-wide settings) will be used.
- access
- If ‘userspace’, instance will access this disk directly without going through a block device, avoiding expensive context switches with kernel space. This option works only for RBD, Gluster and ExtStorage devices. If not specified, the default access of the node-group (possibly inherited from the cluster-wide settings) will be used.
When creating ExtStorage disks, also arbitrary parameters can be passed,
to the ExtStorage provider. Those parameters are passed as additional
comma separated options. Therefore, an ExtStorage disk provided by
provider pvdr1 with parameters param1, param2 would be
passed as --disk 0:size=10G,provider=pvdr1,param1=val1,param2=val2.
When using the adopt key in the disk definition, Ganeti will
reuse those volumes (instead of creating new ones) as the
instance’s disks. Ganeti will rename these volumes to the standard
format, and (without installing the OS) will use them as-is for the
instance. This allows migrating instances from non-managed mode
(e.g. plain KVM with LVM) to being managed via Ganeti. Please note that
this works only for the `plain’ disk template (see below for
template details).
Alternatively, a single-disk instance can be created via the -s
option which takes a single argument, the size of the disk. This is
similar to the Ganeti 1.2 version (but will only create one disk).
The minimum disk specification is therefore --disk 0:size=20G (or
-s 20G when using the -s option), and a three-disk instance
can be specified as --disk 0:size=20G --disk 1:size=4G --disk
2:size=100G.
The minimum information needed to specify an ExtStorage disk are the
size and the provider. For example:
--disk 0:size=20G,provider=pvdr1.
The --no-ip-check skips the checks that are done to see if the
instance’s IP is not already alive (i.e. reachable from the master
node).
The --no-name-check skips the check for the instance name via
the resolver (e.g. in DNS or /etc/hosts, depending on your setup).
Since the name check is used to compute the IP address, if you pass
this option you must also pass the --no-ip-check option.
If you don’t want the instance to automatically start after
creation, this is possible via the --no-start option. This will
leave the instance down until a subsequent gnt-instance start
command.
The NICs of the instances can be specified via the --net
option. By default, one NIC is created for the instance, with a
random MAC, and set up according to the cluster level NIC
parameters. Each NIC can take these parameters (all optional):
- mac
- either a value or ‘generate’ to generate a new unique MAC
- ip
- specifies the IP address assigned to the instance from the Ganeti
side (this is not necessarily what the instance will use, but what
the node expects the instance to use). Note that if an IP in the
range of a network configured with gnt-network(8) is used,
and the NIC is not already connected to it, this network has to be
passed in the network parameter if this NIC is meant to be
connected to the said network.
--no-conflicts-checkcan be used to override this check. The special value pool causes Ganeti to select an IP from the network the NIC is or will be connected to. One can pick an externally reserved IP of a network along with--no-conflict-check. Note that this IP cannot be assigned to any other instance until it gets released. - mode
- specifies the connection mode for this NIC: routed, bridged or openvswitch.
- link
- in bridged or openvswitch mode specifies the interface to attach this NIC to, in routed mode it’s intended to differentiate between different routing tables/instance groups (but the meaning is dependent on the network script, see gnt-cluster(8) for more details). Note that openvswitch support is also hypervisor dependent.
- network
- derives the mode and the link from the settings of the network which is identified by its name. If the network option is chosen, link and mode must not be specified. Note that the mode and link depend on the network-to-nodegroup connection, thus allowing different nodegroups to be connected to the same network in different ways.
- name
- this option specifies a name for the NIC, which can be used as a NIC identifier. An instance can not have two NICs with the same name.
- vlan
- in openvswitch mode specifies the VLANs that the NIC will be
connected to. To connect as an access port use
nor.nwith n being the VLAN ID. To connect as an trunk port use:n[:n]. A hybrid port can be created with.n:n[:n]
Of these “mode” and “link” are NIC parameters, and inherit their
default at cluster level. Alternatively, if no network is desired for
the instance, you can prevent the default of one NIC with the
--no-nics option.
The -o (--os-type) option specifies the operating system to be
installed. The available operating systems can be listed with
gnt-os list. Passing --no-install will however skip the OS
installation, allowing a manual import if so desired. Note that the
no-installation mode will automatically disable the start-up of the
instance (without an OS, it most likely won’t be able to start-up
successfully).
Passing the --forthcoming option, Ganeti will not at all try
to create the instance or its disks. Instead the instance will
only be added to the configuration, so that the resources are reserved.
If the --commit option is passed, then it is a prerequisite that
an instance with that name has already been added to the configuration
as a forthcoming instance and the request is to replace this instance
by the newly created real one.
Note that if the reason for reserving an instance is that DNS names
still need to be propagated, the reservation has to be done with
--no-name-check and --no-ip-check as these options are not
implied by --forthcoming.
The -B (--backend-parameters) option specifies the backend
parameters for the instance. If no such parameters are specified, the
values are inherited from the cluster. Possible parameters are:
- maxmem
- the maximum memory size of the instance; as usual, suffixes can be used to denote the unit, otherwise the value is taken in mebibytes
- minmem
- the minimum memory size of the instance; as usual, suffixes can be used to denote the unit, otherwise the value is taken in mebibytes
- vcpus
- the number of VCPUs to assign to the instance (if this value makes sense for the hypervisor)
- auto_balance
- whether the instance is considered in the N+1 cluster checks (enough redundancy in the cluster to survive a node failure)
- always_failover
TrueorFalse, whether the instance must be failed over (shut down and rebooted) always or it may be migrated (briefly suspended)
Note that before 2.6 Ganeti had a memory parameter, which was the
only value of memory an instance could have. With the
maxmem/minmem change Ganeti guarantees that at least the minimum
memory is always available for an instance, but allows more memory to be
used (up to the maximum memory) should it be free.
The -H (--hypervisor-parameters) option specified the hypervisor
to use for the instance (must be one of the enabled hypervisors on the
cluster) and optionally custom parameters for this instance. If not
other options are used (i.e. the invocation is just -H NAME) the
instance will inherit the cluster options. The defaults below show the
cluster defaults at cluster creation time.
The possible hypervisor options are as follows:
- boot_order
Valid for the Xen HVM and KVM hypervisors.
A string value denoting the boot order. This has different meaning for the Xen HVM hypervisor and for the KVM one.
For Xen HVM, The boot order is a string of letters listing the boot devices, with valid device letters being:
- a
- floppy drive
- c
- hard disk
- d
- CDROM drive
- n
- network boot (PXE)
The default is not to set an HVM boot order, which is interpreted as ‘dc’.
For KVM the boot order is either “floppy”, “cdrom”, “disk” or “network”. Please note that older versions of KVM couldn’t netboot from virtio interfaces. This has been fixed in more recent versions and is confirmed to work at least with qemu-kvm 0.11.1. Also note that if you have set the
kernel_pathoption, that will be used for booting, and this setting will be silently ignored.- blockdev_prefix
Valid for the Xen HVM and PVM hypervisors.
Relevant to non-pvops guest kernels, in which the disk device names are given by the host. Allows one to specify ‘xvd’, which helps run Red Hat based installers, driven by anaconda.
- floppy_image_path
Valid for the KVM hypervisor.
The path to a floppy disk image to attach to the instance. This is useful to install Windows operating systems on Virt/IO disks because you can specify here the floppy for the drivers at installation time.
- cdrom_image_path
Valid for the Xen HVM and KVM hypervisors.
The path to a CDROM image to attach to the instance.
- cdrom2_image_path
Valid for the KVM hypervisor.
The path to a second CDROM image to attach to the instance. NOTE: This image can’t be used to boot the system. To do that you have to use the ‘cdrom_image_path’ option.
- nic_type
Valid for the Xen HVM and KVM hypervisors.
This parameter determines the way the network cards are presented to the instance. The possible options are:
- rtl8139 (default for Xen HVM) (HVM & KVM)
- ne2k_isa (HVM & KVM)
- ne2k_pci (HVM & KVM)
- i82551 (KVM)
- i82557b (KVM)
- i82559er (KVM)
- pcnet (KVM)
- e1000 (KVM)
- paravirtual (default for KVM) (HVM & KVM)
- vif_type
Valid for the Xen HVM hypervisor.
This parameter specifies the vif type of the nic configuration of the instance. Unsetting the value leads to no type being specified in the configuration. Note that this parameter only takes effect when the ‘nic_type’ is not set. The possible options are:
- ioemu
- vif
- scsi_controller_type
Valid for the KVM hypervisor.
This parameter specifies which type of SCSI controller to use. The possible options are:
- lsi [default]
- megasas
- virtio-scsi-pci
- kvm_pci_reservations
Valid for the KVM hypervisor.
The nubmer of PCI slots that QEMU will manage implicitly. By default Ganeti will let QEMU use the first 12 slots (i.e. PCI slots 0-11) on its own and will start adding disks and NICs from the 13rd slot (i.e. PCI slot 12) onwards. So by default one can add 20 PCI devices (32 - 12). To support more than that, this hypervisor parameter should be set accordingly (e.g. to 8).
- disk_type
Valid for the Xen HVM and KVM hypervisors.
This parameter determines the way the disks are presented to the instance. The possible options are:
- ioemu [default] (HVM & KVM)
- paravirtual (HVM & KVM)
- ide (KVM)
- scsi (KVM)
- sd (KVM)
- mtd (KVM)
- pflash (KVM)
- cdrom_disk_type
Valid for the KVM hypervisor.
This parameter determines the way the cdroms disks are presented to the instance. The default behavior is to get the same value of the earlier parameter (disk_type). The possible options are:
- paravirtual
- ide
- scsi
- sd
- mtd
- pflash
- vnc_bind_address
Valid for the Xen HVM and KVM hypervisors.
Specifies the address that the VNC listener for this instance should bind to. Valid values are IPv4 addresses. Use the address 0.0.0.0 to bind to all available interfaces (this is the default) or specify the address of one of the interfaces on the node to restrict listening to that interface.
- vnc_password_file
Valid for the Xen HVM and KVM hypervisors.
Specifies the location of the file containing the password for connections using VNC. The default is a file named vnc-cluster-password which can be found in the configuration directory.
- vnc_tls
Valid for the KVM hypervisor.
A boolean option that controls whether the VNC connection is secured with TLS.
- vnc_x509_path
Valid for the KVM hypervisor.
If
vnc_tlsis enabled, this options specifies the path to the x509 certificate to use.- vnc_x509_verify
- Valid for the KVM hypervisor.
- spice_bind
Valid for the KVM hypervisor.
Specifies the address or interface on which the SPICE server will listen. Valid values are:
- IPv4 addresses, including 0.0.0.0 and 127.0.0.1
- IPv6 addresses, including :: and ::1
- names of network interfaces
If a network interface is specified, the SPICE server will be bound to one of the addresses of that interface.
- spice_ip_version
Valid for the KVM hypervisor.
Specifies which version of the IP protocol should be used by the SPICE server.
It is mainly intended to be used for specifying what kind of IP addresses should be used if a network interface with both IPv4 and IPv6 addresses is specified via the
spice_bindparameter. In this case, if thespice_ip_versionparameter is not used, the default IP version of the cluster will be used.- spice_password_file
Valid for the KVM hypervisor.
Specifies a file containing the password that must be used when connecting via the SPICE protocol. If the option is not specified, passwordless connections are allowed.
- spice_image_compression
Valid for the KVM hypervisor.
Configures the SPICE lossless image compression. Valid values are:
- auto_glz
- auto_lz
- quic
- glz
- lz
- off
- spice_jpeg_wan_compression
Valid for the KVM hypervisor.
Configures how SPICE should use the jpeg algorithm for lossy image compression on slow links. Valid values are:
- auto
- never
- always
- spice_zlib_glz_wan_compression
Valid for the KVM hypervisor.
Configures how SPICE should use the zlib-glz algorithm for lossy image compression on slow links. Valid values are:
- auto
- never
- always
- spice_streaming_video
Valid for the KVM hypervisor.
Configures how SPICE should detect video streams. Valid values are:
- off
- all
- filter
- spice_playback_compression
Valid for the KVM hypervisor.
Configures whether SPICE should compress audio streams or not.
- spice_use_tls
Valid for the KVM hypervisor.
Specifies that the SPICE server must use TLS to encrypt all the traffic with the client.
- spice_tls_ciphers
Valid for the KVM hypervisor.
Specifies a list of comma-separated ciphers that SPICE should use for TLS connections. For the format, see man cipher(1).
- spice_use_vdagent
Valid for the KVM hypervisor.
Enables or disables passing mouse events via SPICE vdagent.
- cpu_type
Valid for the KVM hypervisor.
This parameter determines the emulated cpu for the instance. If this parameter is empty (which is the default configuration), it will not be passed to KVM.
Be aware of setting this parameter to
"host"if you have nodes with different CPUs from each other. Live migration may stop working in this situation.For more information please refer to the KVM manual.
- acpi
Valid for the Xen HVM and KVM hypervisors.
A boolean option that specifies if the hypervisor should enable ACPI support for this instance. By default, ACPI is disabled.
ACPI should be enabled for user shutdown detection. See
user_shutdown.- pae
Valid for the Xen HVM and KVM hypervisors.
A boolean option that specifies if the hypervisor should enable PAE support for this instance. The default is false, disabling PAE support.
- viridian
Valid for the Xen HVM hypervisor.
A boolean option that specifies if the hypervisor should enable viridian (Hyper-V) for this instance. The default is false, disabling viridian support.
- use_guest_agent
Valid for the KVM hypervisor.
A boolean option that specifies if the hypervisor should enable the QEMU Guest Agent protocol for this instance. By default, the Guest Agent is disabled.
- use_localtime
Valid for the Xen HVM and KVM hypervisors.
A boolean option that specifies if the instance should be started with its clock set to the localtime of the machine (when true) or to the UTC (When false). The default is false, which is useful for Linux/Unix machines; for Windows OSes, it is recommended to enable this parameter.
- kernel_path
Valid for the Xen PVM and KVM hypervisors.
This option specifies the path (on the node) to the kernel to boot the instance with. Xen PVM instances always require this, while for KVM if this option is empty, it will cause the machine to load the kernel from its disks (and the boot will be done accordingly to
boot_order).- kernel_args
Valid for the Xen PVM and KVM hypervisors.
This options specifies extra arguments to the kernel that will be loaded. This is always used for Xen PVM, while for KVM it is only used if the
kernel_pathoption is also specified.The default setting for this value is simply
"ro", which mounts the root disk (initially) in read-only one. For example, setting this to single will cause the instance to start in single-user mode.Note that the hypervisor setting
serial_consoleappends"console=ttyS0,<serial_speed>"to the end ofkernel_argsin KVM.- initrd_path
Valid for the Xen PVM and KVM hypervisors.
This option specifies the path (on the node) to the initrd to boot the instance with. Xen PVM instances can use this always, while for KVM if this option is only used if the
kernel_pathoption is also specified. You can pass here either an absolute filename (the path to the initrd) if you want to use an initrd, or use the format no_initrd_path for no initrd.- root_path
Valid for the Xen PVM and KVM hypervisors.
This options specifies the name of the root device. This is always needed for Xen PVM, while for KVM it is only used if the
kernel_pathoption is also specified.Please note, that if this setting is an empty string and the hypervisor is Xen it will not be written to the Xen configuration file
- serial_console
Valid for the KVM hypervisor.
This boolean option specifies whether to emulate a serial console for the instance. Note that some versions of KVM have a bug that will make an instance hang when configured to use the serial console unless a connection is made to it within about 2 seconds of the instance’s startup. For such case it’s recommended to disable this option, which is enabled by default.
Enabling serial console emulation also appends
"console=ttyS0,<serial_speed>"to the end ofkernel_argsin KVM and may infere with previous settings.- serial_speed
Valid for the KVM hypervisor.
This integer option specifies the speed of the serial console. Common values are 9600, 19200, 38400, 57600 and 115200: choose the one which works on your system. (The default is 38400 for historical reasons, but newer versions of kvm/qemu work with 115200)
- disk_cache
Valid for the KVM hypervisor.
The disk cache mode. It can be either default to not pass any cache option to KVM, or one of the KVM cache modes: none (for direct I/O), writethrough (to use the host cache but report completion to the guest only when the host has committed the changes to disk) or writeback (to use the host cache and report completion as soon as the data is in the host cache). Note that there are special considerations for the cache mode depending on version of KVM used and disk type (always raw file under Ganeti), please refer to the KVM documentation for more details.
- disk_aio
Valid for the KVM hypervisor.
This is an optional parameter that specifies the aio mode for the disks. KVM default is to use the ‘threads’ mode, so if not explicitly specified, the native mode will not be used. Possible values are: threads or native.
- disk_discard
Valid for the KVM hypervisor.
discard is one of “ignore”, “unmap” or “default” and controls whether discard (also known as trim or unmap) requests are ignored or passed to the filesystem. Some machine types may not support discard requests. For compatibility with older qemu versions “default” will not pass any discard option to KVM.
- security_model
Valid for the KVM hypervisor.
The security model for kvm. Currently one of none, user or pool. Under none, the default, nothing is done and instances are run as the Ganeti daemon user (normally root).
Under user kvm will drop privileges and become the user specified by the security_domain parameter.
Under pool a global cluster pool of users will be used, making sure no two instances share the same user on the same node. (this mode is not implemented yet)
- security_domain
Valid for the KVM hypervisor.
Under security model user the username to run the instance under. It must be a valid username existing on the host.
Cannot be set under security model none or pool.
- kvm_flag
Valid for the KVM hypervisor.
If enabled the -enable-kvm flag is passed to kvm. If disabled -disable-kvm is passed. If unset no flag is passed, and the default running mode for your kvm binary will be used.
- mem_path
Valid for the KVM hypervisor.
This option passes the -mem-path argument to kvm with the path (on the node) to the mount point of the hugetlbfs file system, along with the -mem-prealloc argument too.
- use_chroot
Valid for the KVM hypervisor.
This boolean option determines whether to run the KVM instance in a chroot directory.
If it is set to
true, an empty directory is created before starting the instance and its path is passed via the -chroot flag to kvm. The directory is removed when the instance is stopped.It is set to
falseby default.- user_shutdown
Valid for the KVM hypervisor.
This boolean option determines whether the KVM instance suports user shutdown detection. This option does not necessarily require ACPI enabled, but ACPI must be enabled for users to poweroff their KVM instances.
If it is set to
true, the user can shutdown this KVM instance and its status is reported asUSER_down.It is set to
falseby default.- migration_downtime
Valid for the KVM hypervisor.
The maximum amount of time (in ms) a KVM instance is allowed to be frozen during a live migration, in order to copy dirty memory pages. Default value is 30ms, but you may need to increase this value for busy instances.
This option is only effective with kvm versions >= 87 and qemu-kvm versions >= 0.11.0.
- cpu_mask
Valid for the Xen, KVM and LXC hypervisors.
The processes belonging to the given instance are only scheduled on the specified CPUs.
The format of the mask can be given in three forms. First, the word “all”, which signifies the common case where all VCPUs can live on any CPU, based on the hypervisor’s decisions.
Second, a comma-separated list of CPU IDs or CPU ID ranges. The ranges are defined by a lower and higher boundary, separated by a dash, and the boundaries are inclusive. In this form, all VCPUs of the instance will be mapped on the selected list of CPUs. Example:
0-2,5, mapping all VCPUs (no matter how many) onto physical CPUs 0, 1, 2 and 5.The last form is used for explicit control of VCPU-CPU pinnings. In this form, the list of VCPU mappings is given as a colon (:) separated list, whose elements are the possible values for the second or first form above. In this form, the number of elements in the colon-separated list _must_ equal the number of VCPUs of the instance.
Example:
# Map the entire instance to CPUs 0-2 gnt-instance modify -H cpu_mask=0-2 my-inst # Map vCPU 0 to physical CPU 1 and vCPU 1 to CPU 3 (assuming 2 vCPUs) gnt-instance modify -H cpu_mask=1:3 my-inst # Pin vCPU 0 to CPUs 1 or 2, and vCPU 1 to any CPU gnt-instance modify -H cpu_mask=1-2:all my-inst # Pin vCPU 0 to any CPU, vCPU 1 to CPUs 1, 3, 4 or 5, and CPU 2 to # CPU 0 (backslashes for escaping the comma) gnt-instance modify -H cpu_mask=all:1\\,3-5:0 my-inst # Pin entire VM to CPU 0 gnt-instance modify -H cpu_mask=0 my-inst # Turn off CPU pinning (default setting) gnt-instance modify -H cpu_mask=all my-inst
- cpu_cap
Valid for the Xen hypervisor.
Set the maximum amount of cpu usage by the VM. The value is a percentage between 0 and (100 * number of VCPUs). Default cap is 0: unlimited.
- cpu_weight
Valid for the Xen hypervisor.
Set the cpu time ratio to be allocated to the VM. Valid values are between 1 and 65535. Default weight is 256.
- usb_mouse
Valid for the KVM hypervisor.
This option specifies the usb mouse type to be used. It can be “mouse” or “tablet”. When using VNC it’s recommended to set it to “tablet”.
- keymap
Valid for the KVM hypervisor.
This option specifies the keyboard mapping to be used. It is only needed when using the VNC console. For example: “fr” or “en-gb”.
- reboot_behavior
Valid for Xen PVM, Xen HVM and KVM hypervisors.
Normally if an instance reboots, the hypervisor will restart it. If this option is set to
exit, the hypervisor will treat a reboot as a shutdown instead.It is set to
rebootby default.- cpu_cores
Valid for the KVM hypervisor.
Number of emulated CPU cores.
- cpu_threads
Valid for the KVM hypervisor.
Number of emulated CPU threads.
- cpu_sockets
Valid for the KVM hypervisor.
Number of emulated CPU sockets.
- soundhw
Valid for Xen PVM, Xen HVM and KVM hypervisors.
Comma separated list of emulated sounds cards, or “all” to enable all the available ones. See the qemu(1) manpage for valid options and additional details.
- cpuid
Valid for the XEN hypervisor.
Modify the values returned by CPUID instructions run within instances.
This allows you to enable migration between nodes with different CPU attributes like cores, threads, hyperthreading or SS4 support by hiding the extra features where needed.
See the XEN documentation for syntax and more information.
- usb_devices
Valid for the KVM hypervisor.
Space separated list of usb devices. These can be emulated devices or passthrough ones, and each one gets passed to kvm with its own
-usbdeviceoption. See the qemu(1) manpage for the syntax of the possible components. Note that values set with this parameter are split on a space character and currently don’t support quoting. For backwards compatibility reasons, the RAPI interface keeps accepting comma separated lists too.- vga
Valid for the KVM hypervisor.
Emulated vga mode, passed the the kvm -vga option.
- kvm_extra
Valid for the KVM hypervisor.
Any other option to the KVM hypervisor, useful tweaking anything that Ganeti doesn’t support. Note that values set with this parameter are split on a space character and currently don’t support quoting.
- machine_version
Valid for the KVM hypervisor.
Use in case an instance must be booted with an exact type of machine version (due to e.g. outdated drivers). In case it’s not set the default version supported by your version of kvm is used.
- migration_caps
Valid for the KVM hypervisor.
Enable specific migration capabilities by providing a ”:” separated list of supported capabilites. QEMU version 1.7.0 defines x-rdma-pin-all, auto-converge, zero-blocks, and xbzrle. Please note that while a combination of xbzrle and auto-converge might speed up the migration process significantly, the first may cause BSOD on Windows8r2 instances running on drbd.
- kvm_path
Valid for the KVM hypervisor.
Path to the userspace KVM (or qemu) program.
- vnet_hdr
Valid for the KVM hypervisor.
This boolean option determines whether the tap devices used by the KVM paravirtual nics (virtio-net) will get created with VNET_HDR (IFF_VNET_HDR) support.
If set to false, it effectively disables offloading on the virio-net interfaces, which prevents host kernel tainting and log flooding, when dealing with broken or malicious virtio-net drivers.
It is set to
trueby default.- virtio_net_queues
Valid for the KVM hypervisor.
Set a number of queues (file descriptors) for tap device to parallelize packets sending or receiving. Tap devices will be created with MULTI_QUEUE (IFF_MULTI_QUEUE) support. This only works with KVM paravirtual nics (virtio-net) and the maximum number of queues is limited to
8. Tehnically this is an extension ofvnet_hdrwhich must be enabled for multiqueue support.If set to
1queue, it effectively disables multiqueue support on the tap and virio-net devices.For instances it is necessary to manually set number of queues (on Linux using:
ethtool -L ethX combined $queues).It is set to
1by default.- startup_timeout
Valid for the LXC hypervisor.
This integer option specifies the number of seconds to wait for the state of an LXC container changes to “RUNNING” after startup, as reported by lxc-wait. Otherwise we assume an error has occurred and report it.
It is set to
30by default.- extra_cgroups
Valid for the LXC hypervisor.
This option specifies the list of cgroup subsystems that will be mounted alongside the needed ones before starting LXC containers.
Since LXC version >= 1.0.0, LXC strictly requires all cgroup subsystems to be mounted before starting a container. Users can control the list of desired cgroup subsystems for LXC containers by specifying the lxc.cgroup.use parameter in the LXC system configuration file(see: lxc.system.conf(5)). Its default value is “@kernel” which means all cgroup kernel subsystems.
The LXC hypervisor of Ganeti ensures that all cgroup subsystems needed to start an LXC container are mounted, as well as the subsystems specified in this parameter. The needed subsystems are currently
cpuset,memory,devices, andcpuacct.The value of this parameter should be a list of cgroup subsystems separated by a comma(e.g., “net_cls,perf_event,blkio”).
If this parameter is not specified, a list of subsystems will be taken from /proc/cgroups instead.
- drop_capabilities
Valid for the LXC hypervisor.
This option specifies the list of capabilities which should be dropped for a LXC container. Each value of this option must be in the same form as the lxc.cap.drop configuration parameter of lxc.container.conf(5). It is the lower case of the capability name without the “CAP_” prefix (e.g., “sys_module,sys_time”). See capabilities(7) for more details about Linux capabilities. Note that some capabilities are required by the LXC container (see: lxc.container.conf(5)). Also note that the CAP_SYS_BOOT is required(should not be dropped) to perform the soft reboot for the LXC container.
The default value is
mac_override,sys_boot,sys_module,sys_time.- devices
Valid for the LXC hypervisor.
This option specifies the list of devices that can be accessed from inside of the LXC container. Each value of this option must have the same form as the lxc.cgroup.devices.allow configuration parameter of lxc.container.conf(5). It consists of the type(a: all, b: block, c: character), the major-minor pair, and the access type sequence(r: read, w: write, m: mknod), e.g. “c 1:3 rw”. If you’d like to allow the LXC container to access /dev/null and /dev/zero with read-write access, you can set this parameter to: “c 1:3 rw,c 1:5 rw”. The LXC hypervisor drops all direct device access by default, so if you want to allow the LXC container to access an additional device which is not included in the default value of this parameter, you have to set this parameter manually.
By default, this parameter contains (/dev/null, /dev/zero, /dev/full, /dev/random, /dev/urandom, /dev/aio, /dev/tty, /dev/console, /dev/ptmx and first block of Unix98 PTY slaves) with read-write(rw) access.
- extra_config
Valid for the LXC hypervisor.
This option specifies the list of extra config parameters which are not supported by the Ganeti LXC hypervisor natively. Each value of this option must be a valid line of the LXC container config file(see: lxc.container.conf(5)).
This parameter is not set by default.
- num_ttys
Valid for the LXC hypervisor.
This option specifies the number of ttys(actually ptys) that should be allocated for the LXC container. You can disable pty devices allocation for the LXC container by setting this parameter to 0, but you can’t use gnt-instance console in this case.
It is set to
6by default.
The -O (--os-parameters) option allows customisation of the OS
parameters. The actual parameter names and values depend on the OS being
used, but the syntax is the same key=value. For example, setting a
hypothetical dhcp parameter to yes can be achieved by:
gnt-instance add -O dhcp=yes ...
You can also specify OS parameters that should not be logged but reused
at the next reinstall with --os-parameters-private and OS parameters
that should not be logged or saved to configuration with
--os-parameters-secret. Bear in mind that:
- Launching the daemons in debug mode will cause debug logging to happen, which leaks private and secret parameters to the log files. Do not use the debug mode in production. Deamons will emit a warning on startup if they are in debug mode.
- You will have to pass again all
--os-parameters-secretparameters should you want to reinstall this instance.
The -I (--iallocator) option specifies the instance allocator plugin
to use (. means the default allocator). If you pass in this option
the allocator will select nodes for this instance automatically, so you
don’t need to pass them with the -n option. For more information
please refer to the instance allocator documentation.
The -g (--node-group) option can be used to create the instance
in a particular node group, specified by name.
The -t (--disk-template) options specifies the disk layout type
for the instance. If no disk template is specified, the default disk
template is used. The default disk template is the first in the list
of enabled disk templates, which can be adjusted cluster-wide with
gnt-cluster modify. The available choices for disk templates are:
- diskless
- This creates an instance with no disks. Its useful for testing only (or other special cases).
- file
- Disk devices will be regular files.
- sharedfile
- Disk devices will be regulare files on a shared directory.
- plain
- Disk devices will be logical volumes.
- drbd
- Disk devices will be drbd (version 8.x) on top of lvm volumes.
- rbd
- Disk devices will be rbd volumes residing inside a RADOS cluster.
- blockdev
- Disk devices will be adopted pre-existent block devices.
- ext
- Disk devices will be provided by external shared storage, through the ExtStorage Interface using ExtStorage providers.
The optional second value of the -n (--node) is used for the drbd
template type and specifies the remote node.
If you do not want gnt-instance to wait for the disk mirror to be
synced, use the --no-wait-for-sync option.
The --file-storage-dir specifies the relative path under the
cluster-wide file storage directory to store file-based disks. It is
useful for having different subdirectories for different
instances. The full path of the directory where the disk files are
stored will consist of cluster-wide file storage directory + optional
subdirectory + instance name. This option is only relevant for
instances using the file storage backend.
The --file-driver specifies the driver to use for file-based
disks. Note that currently these drivers work with the xen hypervisor
only. This option is only relevant for instances using the file
storage backend. The available choices are:
- loop
- Kernel loopback driver. This driver uses loopback devices to access the filesystem within the file. However, running I/O intensive applications in your instance using the loop driver might result in slowdowns. Furthermore, if you use the loopback driver consider increasing the maximum amount of loopback devices (on most systems it’s 8) using the max_loop param.
- blktap
- The blktap driver (for Xen hypervisors). In order to be able to use the blktap driver you should check if the ‘blktapctrl’ user space disk agent is running (usually automatically started via xend). This user-level disk I/O interface has the advantage of better performance. Especially if you use a network file system (e.g. NFS) to store your instances this is the recommended choice.
- blktap2
- Analogous to the blktap driver, but used by newer versions of Xen.
If --ignore-ipolicy is given any instance policy violations occuring
during this operation are ignored.
The -c and --communication specify whether to enable/disable
instance communication, which is a communication mechanism between the
instance and the host.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance add -t file --disk 0:size=30g -B maxmem=512 -o debian-etch \
-n node1.example.com --file-storage-dir=mysubdir instance1.example.com
# gnt-instance add -t plain --disk 0:size=30g -B maxmem=1024,minmem=512 \
-o debian-etch -n node1.example.com instance1.example.com
# gnt-instance add -t plain --disk 0:size=30g --disk 1:size=100g,vg=san \
-B maxmem=512 -o debian-etch -n node1.example.com instance1.example.com
# gnt-instance add -t drbd --disk 0:size=30g -B maxmem=512 -o debian-etch \
-n node1.example.com:node2.example.com instance2.example.com
# gnt-instance add -t rbd --disk 0:size=30g -B maxmem=512 -o debian-etch \
-n node1.example.com instance1.example.com
# gnt-instance add -t ext --disk 0:size=30g,provider=pvdr1 -B maxmem=512 \
-o debian-etch -n node1.example.com instance1.example.com
# gnt-instance add -t ext --disk 0:size=30g,provider=pvdr1,param1=val1 \
--disk 1:size=40g,provider=pvdr2,param2=val2,param3=val3 -B maxmem=512 \
-o debian-etch -n node1.example.com instance1.example.com
BATCH-CREATE¶
This command (similar to the Ganeti 1.2 batcher tool) submits
multiple instance creation jobs based on a definition file. This
file can contain all options which are valid when adding an instance
with the exception of the iallocator field. The IAllocator is,
for optimization purposes, only allowed to be set for the whole batch
operation using the --iallocator parameter.
The instance file must be a valid-formed JSON file, containing an
array of dictionaries with instance creation parameters. All parameters
(except iallocator) which are valid for the instance creation
OP code are allowed. The most important ones are:
- instance_name
- The FQDN of the new instance.
- disk_template
- The disk template to use for the instance, the same as in the add command.
- disks
- Array of disk specifications. Each entry describes one disk as a dictionary of disk parameters.
- beparams
- A dictionary of backend parameters.
- hypervisor
- The hypervisor for the instance.
- hvparams
- A dictionary with the hypervisor options. If not passed, the default hypervisor options will be inherited.
- nics
- List of NICs that will be created for the instance. Each entry should be a dict, with mac, ip, mode and link as possible keys. Please don’t provide the “mac, ip, mode, link” parent keys if you use this method for specifying NICs.
- pnode, snode
- The primary and optionally the secondary node to use for the instance (in case an iallocator script is not used). If those parameters are given, they have to be given consistently for all instances in the batch operation.
- start
- whether to start the instance
- ip_check
- Skip the check for already-in-use instance; see the description in the add command for details.
- name_check
- Skip the name check for instances; see the description in the add command for details.
- file_storage_dir, file_driver
- Configuration for the file disk type, see the add command for details.
A simple definition for one instance can be (with most of the parameters taken from the cluster defaults):
[
{
"mode": "create",
"instance_name": "instance1.example.com",
"disk_template": "drbd",
"os_type": "debootstrap",
"disks": [{"size":"1024"}],
"nics": [{}],
"hypervisor": "xen-pvm"
},
{
"mode": "create",
"instance_name": "instance2.example.com",
"disk_template": "drbd",
"os_type": "debootstrap",
"disks": [{"size":"4096", "mode": "rw", "vg": "xenvg"}],
"nics": [{}],
"hypervisor": "xen-hvm",
"hvparams": {"acpi": true},
"beparams": {"maxmem": 512, "minmem": 256}
}
]
The command will display the job id for each submitted instance, as follows:
# gnt-instance batch-create instances.json
Submitted jobs 37, 38
Note: If the allocator is used for computing suitable nodes for the instances, it will only take into account disk information for the default disk template. That means, even if other disk templates are specified for the instances, storage space information of these disk templates will not be considered in the allocation computation.
REMOVE¶
Remove an instance. This will remove all data from the instance and there is no way back. If you are not sure if you use an instance again, use shutdown first and leave it in the shutdown state for a while.
The --ignore-failures option will cause the removal to proceed
even in the presence of errors during the removal of the instance
(e.g. during the shutdown or the disk removal). If this option is not
given, the command will stop at the first error.
The --shutdown-timeout is used to specify how much time to wait
before forcing the shutdown (e.g. xm destroy in Xen, killing the
kvm process for KVM, etc.). By default two minutes are given to each
instance to stop.
The --force option is used to skip the interactive confirmation.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance remove instance1.example.com
LIST¶
Shows the currently configured instances with memory usage, disk usage, the node they are running on, and their run status.
The --no-headers option will skip the initial header line. The
--separator option takes an argument which denotes what will be
used between the output fields. Both these options are to help
scripting.
The units used to display the numeric values in the output varies,
depending on the options given. By default, the values will be
formatted in the most appropriate unit. If the --separator option
is given, then the values are shown in mebibytes to allow parsing by
scripts. In both cases, the --units option can be used to enforce
a given output unit.
The -v option activates verbose mode, which changes the display of
special field states (see ganeti(7)).
The -o (--output) option takes a comma-separated list of output
fields. The available fields and their meaning are:
admin_state- Desired state of the instance
admin_state_source- Who last changed the desired state of the instance
admin_up- Desired state of the instance
be/always_failover- The “always_failover” backend parameter
be/auto_balance- The “auto_balance” backend parameter
be/maxmem- The “maxmem” backend parameter
be/memory- The “maxmem” backend parameter
be/minmem- The “minmem” backend parameter
be/spindle_use- The “spindle_use” backend parameter
be/vcpus- The “vcpus” backend parameter
beparams- Backend parameters (merged)
bridge- Bridge of 1st network interface
console- Instance console information
ctime- Creation timestamp
custom_beparams- Custom backend parameters
custom_hvparams- Custom hypervisor parameters
custom_nicparams- Custom network interface parameters
custom_osparams- Custom operating system parameters
disk.count- Number of disks
disk.name/0- Name of 1st disk
disk.name/1- Name of 2nd disk
disk.name/2- Name of 3rd disk
disk.name/3- Name of 4th disk
disk.name/4- Name of 5th disk
disk.name/5- Name of 6th disk
disk.name/6- Name of 7th disk
disk.name/7- Name of 8th disk
disk.name/8- Name of 9th disk
disk.name/9- Name of 10th disk
disk.name/10- Name of 11th disk
disk.name/11- Name of 12th disk
disk.name/12- Name of 13th disk
disk.name/13- Name of 14th disk
disk.name/14- Name of 15th disk
disk.name/15- Name of 16th disk
disk.names- List of disk names
disk.size/0- Disk size of 1st disk
disk.size/1- Disk size of 2nd disk
disk.size/2- Disk size of 3rd disk
disk.size/3- Disk size of 4th disk
disk.size/4- Disk size of 5th disk
disk.size/5- Disk size of 6th disk
disk.size/6- Disk size of 7th disk
disk.size/7- Disk size of 8th disk
disk.size/8- Disk size of 9th disk
disk.size/9- Disk size of 10th disk
disk.size/10- Disk size of 11th disk
disk.size/11- Disk size of 12th disk
disk.size/12- Disk size of 13th disk
disk.size/13- Disk size of 14th disk
disk.size/14- Disk size of 15th disk
disk.size/15- Disk size of 16th disk
disk.sizes- List of disk sizes
disk.spindles- List of disk spindles
disk.spindles/0- Spindles of 1st disk
disk.spindles/1- Spindles of 2nd disk
disk.spindles/2- Spindles of 3rd disk
disk.spindles/3- Spindles of 4th disk
disk.spindles/4- Spindles of 5th disk
disk.spindles/5- Spindles of 6th disk
disk.spindles/6- Spindles of 7th disk
disk.spindles/7- Spindles of 8th disk
disk.spindles/8- Spindles of 9th disk
disk.spindles/9- Spindles of 10th disk
disk.spindles/10- Spindles of 11th disk
disk.spindles/11- Spindles of 12th disk
disk.spindles/12- Spindles of 13th disk
disk.spindles/13- Spindles of 14th disk
disk.spindles/14- Spindles of 15th disk
disk.spindles/15- Spindles of 16th disk
disk.uuid/0- UUID of 1st disk
disk.uuid/1- UUID of 2nd disk
disk.uuid/2- UUID of 3rd disk
disk.uuid/3- UUID of 4th disk
disk.uuid/4- UUID of 5th disk
disk.uuid/5- UUID of 6th disk
disk.uuid/6- UUID of 7th disk
disk.uuid/7- UUID of 8th disk
disk.uuid/8- UUID of 9th disk
disk.uuid/9- UUID of 10th disk
disk.uuid/10- UUID of 11th disk
disk.uuid/11- UUID of 12th disk
disk.uuid/12- UUID of 13th disk
disk.uuid/13- UUID of 14th disk
disk.uuid/14- UUID of 15th disk
disk.uuid/15- UUID of 16th disk
disk.uuids- List of disk UUIDs
disk_template- Instance disk template
disk_usage- Total disk space used by instance on each of its nodes; this is not the disk size visible to the instance, but the usage on the node
disks_active- Desired state of the instance disks
forthcoming- Whether the Instance is forthcoming
hv/acpi- The “acpi” hypervisor parameter
hv/blockdev_prefix- The “blockdev_prefix” hypervisor parameter
hv/boot_order- The “boot_order” hypervisor parameter
hv/bootloader_args- The “bootloader_args” hypervisor parameter
hv/bootloader_path- The “bootloader_path” hypervisor parameter
hv/cdrom2_image_path- The “cdrom2_image_path” hypervisor parameter
hv/cdrom_disk_type- The “cdrom_disk_type” hypervisor parameter
hv/cdrom_image_path- The “cdrom_image_path” hypervisor parameter
hv/cpu_cap- The “cpu_cap” hypervisor parameter
hv/cpu_cores- The “cpu_cores” hypervisor parameter
hv/cpu_mask- The “cpu_mask” hypervisor parameter
hv/cpu_sockets- The “cpu_sockets” hypervisor parameter
hv/cpu_threads- The “cpu_threads” hypervisor parameter
hv/cpu_type- The “cpu_type” hypervisor parameter
hv/cpu_weight- The “cpu_weight” hypervisor parameter
hv/cpuid- The “cpuid” hypervisor parameter
hv/device_model- The “device_model” hypervisor parameter
hv/devices- The “devices” hypervisor parameter
hv/disk_aio- The “disk_aio” hypervisor parameter
hv/disk_cache- The “disk_cache” hypervisor parameter
hv/disk_discard- The “disk_discard” hypervisor parameter
hv/disk_type- The “disk_type” hypervisor parameter
hv/drop_capabilities- The “drop_capabilities” hypervisor parameter
hv/extra_cgroups- The “extra_cgroups” hypervisor parameter
hv/extra_config- The “extra_config” hypervisor parameter
hv/floppy_image_path- The “floppy_image_path” hypervisor parameter
hv/init_script- The “init_script” hypervisor parameter
hv/initrd_path- The “initrd_path” hypervisor parameter
hv/kernel_args- The “kernel_args” hypervisor parameter
hv/kernel_path- The “kernel_path” hypervisor parameter
hv/keymap- The “keymap” hypervisor parameter
hv/kvm_extra- The “kvm_extra” hypervisor parameter
hv/kvm_flag- The “kvm_flag” hypervisor parameter
hv/kvm_path- The “kvm_path” hypervisor parameter
hv/kvm_pci_reservations- The “kvm_pci_reservations” hypervisor parameter
hv/machine_version- The “machine_version” hypervisor parameter
hv/mem_path- The “mem_path” hypervisor parameter
hv/migration_caps- The “migration_caps” hypervisor parameter
hv/migration_downtime- The “migration_downtime” hypervisor parameter
hv/nic_type- The “nic_type” hypervisor parameter
hv/num_ttys- The “num_ttys” hypervisor parameter
hv/pae- The “pae” hypervisor parameter
hv/pci_pass- The “pci_pass” hypervisor parameter
hv/reboot_behavior- The “reboot_behavior” hypervisor parameter
hv/root_path- The “root_path” hypervisor parameter
hv/scsi_controller_type- The “scsi_controller_type” hypervisor parameter
hv/security_domain- The “security_domain” hypervisor parameter
hv/security_model- The “security_model” hypervisor parameter
hv/serial_console- The “serial_console” hypervisor parameter
hv/serial_speed- The “serial_speed” hypervisor parameter
hv/soundhw- The “soundhw” hypervisor parameter
hv/spice_bind- The “spice_bind” hypervisor parameter
hv/spice_image_compression- The “spice_image_compression” hypervisor parameter
hv/spice_ip_version- The “spice_ip_version” hypervisor parameter
hv/spice_jpeg_wan_compression- The “spice_jpeg_wan_compression” hypervisor parameter
hv/spice_password_file- The “spice_password_file” hypervisor parameter
hv/spice_playback_compression- The “spice_playback_compression” hypervisor parameter
hv/spice_streaming_video- The “spice_streaming_video” hypervisor parameter
hv/spice_tls_ciphers- The “spice_tls_ciphers” hypervisor parameter
hv/spice_use_tls- The “spice_use_tls” hypervisor parameter
hv/spice_use_vdagent- The “spice_use_vdagent” hypervisor parameter
hv/spice_zlib_glz_wan_compression- The “spice_zlib_glz_wan_compression” hypervisor parameter
hv/startup_timeout- The “startup_timeout” hypervisor parameter
hv/usb_devices- The “usb_devices” hypervisor parameter
hv/usb_mouse- The “usb_mouse” hypervisor parameter
hv/use_bootloader- The “use_bootloader” hypervisor parameter
hv/use_chroot- The “use_chroot” hypervisor parameter
hv/use_guest_agent- The “use_guest_agent” hypervisor parameter
hv/use_localtime- The “use_localtime” hypervisor parameter
hv/user_shutdown- The “user_shutdown” hypervisor parameter
hv/vga- The “vga” hypervisor parameter
hv/vhost_net- The “vhost_net” hypervisor parameter
hv/vif_script- The “vif_script” hypervisor parameter
hv/vif_type- The “vif_type” hypervisor parameter
hv/viridian- The “viridian” hypervisor parameter
hv/virtio_net_queues- The “virtio_net_queues” hypervisor parameter
hv/vnc_bind_address- The “vnc_bind_address” hypervisor parameter
hv/vnc_password_file- The “vnc_password_file” hypervisor parameter
hv/vnc_tls- The “vnc_tls” hypervisor parameter
hv/vnc_x509_path- The “vnc_x509_path” hypervisor parameter
hv/vnc_x509_verify- The “vnc_x509_verify” hypervisor parameter
hv/vnet_hdr- The “vnet_hdr” hypervisor parameter
hvparams- Hypervisor parameters (merged)
hypervisor- Hypervisor name
ip- IP address of 1st network interface
mac- MAC address of 1st network interface
mtime- Modification timestamp
name- Instance name
network_port- Instance network port if available (e.g. for VNC console)
nic.bridge/0- Bridge of 1st network interface
nic.bridge/1- Bridge of 2nd network interface
nic.bridge/2- Bridge of 3rd network interface
nic.bridge/3- Bridge of 4th network interface
nic.bridge/4- Bridge of 5th network interface
nic.bridge/5- Bridge of 6th network interface
nic.bridge/6- Bridge of 7th network interface
nic.bridge/7- Bridge of 8th network interface
nic.bridges- List containing each network interface’s bridge
nic.count- Number of network interfaces
nic.ip/0- IP address of 1st network interface
nic.ip/1- IP address of 2nd network interface
nic.ip/2- IP address of 3rd network interface
nic.ip/3- IP address of 4th network interface
nic.ip/4- IP address of 5th network interface
nic.ip/5- IP address of 6th network interface
nic.ip/6- IP address of 7th network interface
nic.ip/7- IP address of 8th network interface
nic.ips- List containing each network interface’s IP address
nic.link/0- Link of 1st network interface
nic.link/1- Link of 2nd network interface
nic.link/2- Link of 3rd network interface
nic.link/3- Link of 4th network interface
nic.link/4- Link of 5th network interface
nic.link/5- Link of 6th network interface
nic.link/6- Link of 7th network interface
nic.link/7- Link of 8th network interface
nic.links- List containing each network interface’s link
nic.mac/0- MAC address of 1st network interface
nic.mac/1- MAC address of 2nd network interface
nic.mac/2- MAC address of 3rd network interface
nic.mac/3- MAC address of 4th network interface
nic.mac/4- MAC address of 5th network interface
nic.mac/5- MAC address of 6th network interface
nic.mac/6- MAC address of 7th network interface
nic.mac/7- MAC address of 8th network interface
nic.macs- List containing each network interface’s MAC address
nic.mode/0- Mode of 1st network interface
nic.mode/1- Mode of 2nd network interface
nic.mode/2- Mode of 3rd network interface
nic.mode/3- Mode of 4th network interface
nic.mode/4- Mode of 5th network interface
nic.mode/5- Mode of 6th network interface
nic.mode/6- Mode of 7th network interface
nic.mode/7- Mode of 8th network interface
nic.modes- List containing each network interface’s mode
nic.name/0- Name address of 1st network interface
nic.name/1- Name address of 2nd network interface
nic.name/2- Name address of 3rd network interface
nic.name/3- Name address of 4th network interface
nic.name/4- Name address of 5th network interface
nic.name/5- Name address of 6th network interface
nic.name/6- Name address of 7th network interface
nic.name/7- Name address of 8th network interface
nic.names- List containing each network interface’s name
nic.network.name/0- Network name of 1st network interface
nic.network.name/1- Network name of 2nd network interface
nic.network.name/2- Network name of 3rd network interface
nic.network.name/3- Network name of 4th network interface
nic.network.name/4- Network name of 5th network interface
nic.network.name/5- Network name of 6th network interface
nic.network.name/6- Network name of 7th network interface
nic.network.name/7- Network name of 8th network interface
nic.network/0- Network of 1st network interface
nic.network/1- Network of 2nd network interface
nic.network/2- Network of 3rd network interface
nic.network/3- Network of 4th network interface
nic.network/4- Network of 5th network interface
nic.network/5- Network of 6th network interface
nic.network/6- Network of 7th network interface
nic.network/7- Network of 8th network interface
nic.networks- List containing each interface’s network
nic.networks.names- List containing each interface’s network
nic.uuid/0- UUID address of 1st network interface
nic.uuid/1- UUID address of 2nd network interface
nic.uuid/2- UUID address of 3rd network interface
nic.uuid/3- UUID address of 4th network interface
nic.uuid/4- UUID address of 5th network interface
nic.uuid/5- UUID address of 6th network interface
nic.uuid/6- UUID address of 7th network interface
nic.uuid/7- UUID address of 8th network interface
nic.uuids- List containing each network interface’s UUID
nic.vlan/0- VLAN of 1st network interface
nic.vlan/1- VLAN of 2nd network interface
nic.vlan/2- VLAN of 3rd network interface
nic.vlan/3- VLAN of 4th network interface
nic.vlan/4- VLAN of 5th network interface
nic.vlan/5- VLAN of 6th network interface
nic.vlan/6- VLAN of 7th network interface
nic.vlan/7- VLAN of 8th network interface
nic.vlans- List containing each network interface’s VLAN
nic_link- Link of 1st network interface
nic_mode- Mode of 1st network interface
nic_network- Network of 1st network interface
oper_ram- Actual memory usage as seen by hypervisor
oper_state- Actual state of instance
oper_vcpus- Actual number of VCPUs as seen by hypervisor
os- Operating system
osparams- Operating system parameters (merged)
pnode- Primary node
pnode.group- Primary node’s group
pnode.group.uuid- Primary node’s group UUID
sda_size- Disk size of 1st disk
sdb_size- Disk size of 2nd disk
serial_no- Instance object serial number, incremented on each modification
snodes- Secondary nodes; usually this will just be one node
snodes.group- Node groups of secondary nodes
snodes.group.uuid- Node group UUIDs of secondary nodes
status- Instance status; “running” if instance is set to be running and actually is, “ADMIN_down” if instance is stopped and is not running, “ERROR_wrongnode” if instance running, but not on its designated primary node, “ERROR_up” if instance should be stopped, but is actually running, “ERROR_down” if instance should run, but doesn’t, “ERROR_nodedown” if instance’s primary node is down, “ERROR_nodeoffline” if instance’s primary node is marked offline, “ADMIN_offline” if instance is offline and does not use dynamic, “USER_down” if the user shutdown the instance resources
tags- Tags
uuid- Instance UUID
vcpus- The “vcpus” backend parameter
If the value of the option starts with the character +, the new
field(s) will be added to the default list. This allows one to quickly
see the default list plus a few other fields, instead of retyping the
entire list of fields.
There is a subtle grouping about the available output fields: all
fields except for oper_state, oper_ram, oper_vcpus and
status are configuration value and not run-time values. So if you
don’t select any of the these fields, the query will be satisfied
instantly from the cluster configuration, without having to ask the
remote nodes for the data. This can be helpful for big clusters when
you only want some data and it makes sense to specify a reduced set of
output fields.
If exactly one argument is given and it appears to be a query filter
(see ganeti(7)), the query result is filtered accordingly. For
ambiguous cases (e.g. a single field name as a filter) the --filter
(-F) option forces the argument to be treated as a filter (e.g.
gnt-instance list -F admin_state).
The default output field list is: name, os, pnode,
admin_state, oper_state, oper_ram.
INFO¶
info [-s | –static] [–roman] {–all | instance-name}
Show detailed information about the given instance(s). This is different from list as it shows detailed data about the instance’s disks (especially useful for the drbd disk template).
If the option -s is used, only information available in the
configuration file is returned, without querying nodes, making the
operation faster.
Use the --all to get info about all instances, rather than
explicitly passing the ones you’re interested in.
The --roman option can be used to cause envy among people who like
ancient cultures, but are stuck with non-latin-friendly cluster
virtualization technologies.
MODIFY¶
Modifies the memory size, number of vcpus, ip address, MAC address and/or NIC parameters for an instance. It can also add and remove disks and NICs to/from the instance. Note that you need to give at least one of the arguments, otherwise the command complains.
The -H (--hypervisor-parameters), -B (--backend-parameters)
and -O (--os-parameters) options specifies hypervisor, backend and
OS parameter options in the form of name=value[,...]. For details
which options can be specified, see the add command.
The -t (--disk-template) option will change the disk template of
the instance. Currently, conversions between all the available
templates are supported, except the diskless and the blockdev
templates. For the blockdev disk template, only partial support is
provided and acts only as a source template. Since these volumes are
adopted pre-existent block devices, conversions targeting this template
are not supported. Also, there is no support for conversions to or from
the diskless template. The instance must be stopped before
attempting the conversion. When changing from the plain to the drbd
disk template, a new secondary node must be specified via the -n
option. The option --no-wait-for-sync can be used when converting
to the drbd template in order to make the instance available for
startup before DRBD has finished resyncing. When changing to a
file-based disk template, i.e., file, sharedfile and
gluster, the file storage directory and the file driver can be
specified via the --file-storage-dir and --file-driver options,
respectively. For more details on these options please refer to the
add command section. When changing to an ext template, the
provider’s name must be specified. Also, arbitrary parameters can be
passed, as additional comma separated options. Those parameters along
with the ExtStorage provider must be passed using either the
--ext-params or -e option. It is not allowed specifying existing
disk parameters such as the size, mode, name, access, adopt, vg, metavg,
provider, or spindles options.
The -m (--runtime-memory) option will change an instance’s runtime
memory to the given size (in MB if a different suffix is not specified),
by ballooning it up or down to the new value.
The --disk add:size=*SIZE*,[options..] option adds a disk to the
instance, and --disk *N*:add,size=*SIZE*,[options..] will add a disk
to the instance at a specific index. The available options are the same
as in the add command (spindles, mode, name, vg,
metavg and access). By default, gnt-instance waits for the disk
mirror to sync.
If you do not want this behavior, use the --no-wait-for-sync option.
When adding an ExtStorage disk, the provider=*PROVIDER* option is
also mandatory and specifies the ExtStorage provider. Also, for
ExtStorage disks arbitrary parameters can be passed as additional comma
separated options, same as in the add command. The
--disk attach:name=*NAME* option attaches an existing disk to the
instance at the last disk index and --disk *N*:attach,name=*NAME*
will attach a disk to the instance at a specific index. The accepted
disk identifiers are its name or uuid. The --disk remove
option will remove the last disk of the instance. Use
--disk `` *ID*:remove`` to remove a disk by its identifier. ID can
be the index of the disk, the disks’s name or the disks’s UUID. The
above apply also to the --disk detach option, which removes a disk
from an instance but keeps it in the configuration and doesn’t destroy
it. The --disk *ID*:modify[,options...] will change the options of
the disk.
Available options are:
- mode
- The access mode. Either
ro(read-only) or the defaultrw(read-write). - name
- This option specifies a name for the disk, which can be used as a disk identifier. An instance can not have two disks with the same name.
The --net *N*:add[,options..] will add a new network interface to
the instance. The available options are the same as in the add
command (mac, ip, link, mode, network). The
--net *ID*,remove will remove the intances’ NIC with ID identifier,
which can be the index of the NIC, the NIC’s name or the NIC’s UUID.
The --net *ID*:modify[,options..] option will change the parameters of
the instance network interface with the ID identifier.
The option -o (--os-type) will change the OS name for the instance
(without reinstallation). In case an OS variant is specified that is
not found, then by default the modification is refused, unless
--force-variant is passed. An invalid OS will also be refused,
unless the --force option is given.
The option --new-primary will set the new primary node of an instance
assuming the disks have already been moved manually. Unless the --force
option is given, it is verified that the instance is no longer running
on its current primary node.
The --online and --offline options are used to transition an
instance into and out of the offline state. An instance can be
turned offline only if it was previously down. The --online option
fails if the instance was not in the offline state, otherwise it
changes instance’s state to down. These modifications take effect
immediately.
If --ignore-ipolicy is given any instance policy violations occuring
during this operation are ignored.
If --hotplug is given any disk and NIC modifications will take
effect without the need of actual reboot. Please note that this feature
is currently supported only for KVM hypervisor and there are some
restrictions: a) NIC/Disk hot-remove should work for QEMU versions >= 1.0
b) instances with chroot or pool/user security model support disk
hot-add only for QEMU version > 1.7 where add-fd QMP command exists c) For
the previous case as well as for NIC hot-add, python-fdsend package must
be installed d) if hotplug fails (for any reason) a warning is printed
but execution is continued e) for existing NIC modification interactive
verification is needed unless --force option is passed.
If --hotplug-if-possible is given then ganeti won’t abort in case
hotplug is not supported. It will continue execution and modification
will take place after reboot. This covers use cases where instances are
not running or hypervisor is not KVM.
See ganeti(7) for a description of --submit and other common
options.
Most of the changes take effect at the next restart. If the instance is running, there is no effect on the instance.
REINSTALL¶
Reinstalls the operating system on the given instance(s). The
instance(s) must be stopped when running this command. If the -o
(--os-type) is specified, the operating system is changed.
The --select-os option switches to an interactive OS reinstall.
The user is prompted to select the OS template from the list of
available OS templates. OS parameters can be overridden using -O
(--os-parameters) (more documentation for this option under the
add command).
Since this is a potentially dangerous command, the user will be
required to confirm this action, unless the -f flag is passed.
When multiple instances are selected (either by passing multiple
arguments or by using the --node, --primary, --secondary
or --all options), the user must pass the --force-multiple
options to skip the interactive confirmation.
See ganeti(7) for a description of --submit and other common
options.
RENAME¶
Renames the given instance. The instance must be stopped when running
this command. The requirements for the new name are the same as for
adding an instance: the new name must be resolvable and the IP it
resolves to must not be reachable (in order to prevent duplicate IPs
the next time the instance is started). The IP test can be skipped if
the --no-ip-check option is passed.
Note that you can rename an instance to its same name, to force re-executing the os-specific rename script for that instance, if needed.
The --no-name-check skips the check for the new instance name via
the resolver (e.g. in DNS or /etc/hosts, depending on your setup) and
that the resolved name matches the provided name. Since the name check
is used to compute the IP address, if you pass this option you must also
pass the --no-ip-check option.
The --force option is used to skip the interactive confirmation
when --no-name-check is passed.
See ganeti(7) for a description of --submit and other common
options.
Starting/stopping/connecting to console¶
STARTUP¶
key=value...]key=value...]Starts one or more instances, depending on the following options. The four available modes are:
- –instance
- will start the instances given as arguments (at least one argument required); this is the default selection
- –node
- will start the instances who have the given node as either primary or secondary
- –primary
- will start all instances whose primary node is in the list of nodes passed as arguments (at least one node required)
- –secondary
- will start all instances whose secondary node is in the list of nodes passed as arguments (at least one node required)
- –all
- will start all instances in the cluster (no arguments accepted)
- –tags
- will start all instances in the cluster with the tags given as arguments
- –node-tags
- will start all instances in the cluster on nodes with the tags given as arguments
- –pri-node-tags
- will start all instances in the cluster on primary nodes with the tags given as arguments
- –sec-node-tags
- will start all instances in the cluster on secondary nodes with the tags given as arguments
Note that although you can pass more than one selection option, the last one wins, so in order to guarantee the desired result, don’t pass more than one such option.
Use --force to start even if secondary disks are failing.
--ignore-offline can be used to ignore offline primary nodes and
mark the instance as started even if the primary is not available.
The --force-multiple will skip the interactive confirmation in the
case the more than one instance will be affected.
The --no-remember option will perform the startup but not change
the state of the instance in the configuration file (if it was stopped
before, Ganeti will still think it needs to be stopped). This can be
used for testing, or for a one shot-start where you don’t want the
watcher to restart the instance if it crashes.
The -H (--hypervisor-parameters) and -B (--backend-parameters)
options specify temporary hypervisor and backend parameters that can
be used to start an instance with modified parameters. They can be
useful for quick testing without having to modify an instance back and
forth, e.g.:
# gnt-instance start -H kernel_args="single" instance1
# gnt-instance start -B maxmem=2048 instance2
The first form will start the instance instance1 in single-user mode, and the instance instance2 with 2GB of RAM (this time only, unless that is the actual instance memory size already). Note that the values override the instance parameters (and not extend them): an instance with “kernel_args=ro” when started with -H kernel_args=single will result in “single”, not “ro single”.
The --paused option is only valid for Xen and kvm hypervisors. This
pauses the instance at the start of bootup, awaiting gnt-instance
console to unpause it, allowing the entire boot process to be
monitored for debugging.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance start instance1.example.com
# gnt-instance start --node node1.example.com node2.example.com
# gnt-instance start --all
SHUTDOWN¶
Stops one or more instances. If the instance cannot be cleanly stopped during a hardcoded interval (currently 2 minutes), it will forcibly stop the instance (equivalent to switching off the power on a physical machine).
The --timeout is used to specify how much time to wait before
forcing the shutdown (e.g. xm destroy in Xen, killing the kvm
process for KVM, etc.). By default two minutes are given to each
instance to stop.
The --instance, --node, --primary, --secondary,
--all, --tags, --node-tags, --pri-node-tags and
--sec-node-tags options are similar as for the startup command
and they influence the actual instances being shutdown.
--ignore-offline can be used to ignore offline primary nodes and
force the instance to be marked as stopped. This option should be used
with care as it can lead to an inconsistent cluster state.
Use --force to be able to shutdown an instance even when it’s marked
as offline. This is useful is an offline instance ends up in the
ERROR_up state, for example.
The --no-remember option will perform the shutdown but not change
the state of the instance in the configuration file (if it was running
before, Ganeti will still thinks it needs to be running). This can be
useful for a cluster-wide shutdown, where some instances are marked as
up and some as down, and you don’t want to change the running state:
you just need to disable the watcher, shutdown all instances with
--no-remember, and when the watcher is activated again it will
restore the correct runtime state for all instances.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance shutdown instance1.example.com
# gnt-instance shutdown --all
REBOOT¶
Reboots one or more instances. The type of reboot depends on the value
of -t (--type). A soft reboot does a hypervisor reboot, a hard reboot
does a instance stop, recreates the hypervisor config for the instance
and starts the instance. A full reboot does the equivalent of
gnt-instance shutdown && gnt-instance startup. The default is
hard reboot.
For the hard reboot the option --ignore-secondaries ignores errors
for the secondary node while re-assembling the instance disks.
The --instance, --node, --primary, --secondary,
--all, --tags, --node-tags, --pri-node-tags and
--sec-node-tags options are similar as for the startup command
and they influence the actual instances being rebooted.
The --shutdown-timeout is used to specify how much time to wait
before forcing the shutdown (xm destroy in xen, killing the kvm
process, for kvm). By default two minutes are given to each instance
to stop.
The --force-multiple will skip the interactive confirmation in the
case the more than one instance will be affected.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance reboot instance1.example.com
# gnt-instance reboot --type=full instance1.example.com
CONSOLE¶
console [–show-cmd] {instance}
Connects to the console of the given instance. If the instance is not
up, an error is returned. Use the --show-cmd option to display the
command instead of executing it.
For HVM instances, this will attempt to connect to the serial console of the instance. To connect to the virtualized “physical” console of a HVM instance, use a VNC client with the connection info from the info command.
For Xen/kvm instances, if the instance is paused, this attempts to unpause the instance after waiting a few seconds for the connection to the console to be made.
Example:
# gnt-instance console instance1.example.com
Disk management¶
REPLACE-DISKS¶
This command is a generalized form for replacing disks. It is currently only valid for the mirrored (DRBD) disk template.
The first form (when passing the -p option) will replace the disks
on the primary, while the second form (when passing the -s option
will replace the disks on the secondary node. For these two cases (as
the node doesn’t change), it is possible to only run the replace for a
subset of the disks, using the option --disks which takes a list
of comma-delimited disk indices (zero-based), e.g. 0,2 to replace only
the first and third disks.
The third form (when passing either the --iallocator or the
--new-secondary option) is designed to change secondary node of the
instance. Specifying --iallocator makes the new secondary be
selected automatically by the specified allocator plugin (use . to
indicate the default allocator), otherwise the new secondary node will
be the one chosen manually via the --new-secondary option.
Note that it is not possible to select an offline or drained node as a new secondary.
The fourth form (when using --auto) will automatically determine
which disks of an instance are faulty and replace them within the same
node. The --auto option works only when an instance has only
faulty disks on either the primary or secondary node; it doesn’t work
when both sides have faulty disks.
The --early-release changes the code so that the old storage on
secondary node(s) is removed early (before the resync is completed)
and the internal Ganeti locks for the current (and new, if any)
secondary node are also released, thus allowing more parallelism in
the cluster operation. This should be used only when recovering from a
disk failure on the current secondary (thus the old storage is already
broken) or when the storage on the primary node is known to be fine
(thus we won’t need the old storage for potential recovery).
The --ignore-ipolicy let the command ignore instance policy
violations if replace-disks changes groups and the instance would
violate the new groups instance policy.
See ganeti(7) for a description of --submit and other common
options.
ACTIVATE-DISKS¶
Activates the block devices of the given instance. If successful, the command will show the location and name of the block devices:
node1.example.com:disk/0:/dev/drbd0
node1.example.com:disk/1:/dev/drbd1
In this example, node1.example.com is the name of the node on which the devices have been activated. The disk/0 and disk/1 are the Ganeti-names of the instance disks; how they are visible inside the instance is hypervisor-specific. /dev/drbd0 and /dev/drbd1 are the actual block devices as visible on the node.
The --ignore-size option can be used to activate disks ignoring
the currently configured size in Ganeti. This can be used in cases
where the configuration has gotten out of sync with the real-world
(e.g. after a partially-failed grow-disk operation or due to rounding
in LVM devices). This should not be used in normal cases, but only
when activate-disks fails without it.
The --wait-for-sync option will ensure that the command returns only
after the instance’s disks are synchronised (mostly for DRBD); this can
be useful to ensure consistency, as otherwise there are no commands that
can wait until synchronisation is done. However when passing this
option, the command will have additional output, making it harder to
parse the disk information.
Note that it is safe to run this command while the instance is already running.
See ganeti(7) for a description of --submit and other common
options.
DEACTIVATE-DISKS¶
deactivate-disks [-f] [–submit] [–print-jobid] {instance-name}
De-activates the block devices of the given instance. Note that if you run this command for an instance with a drbd disk template, while it is running, it will not be able to shutdown the block devices on the primary node, but it will shutdown the block devices on the secondary nodes, thus breaking the replication.
The -f/--force option will skip checks that the instance is
down; in case the hypervisor is confused and we can’t talk to it,
normally Ganeti will refuse to deactivate the disks, but with this
option passed it will skip this check and directly try to deactivate
the disks. This can still fail due to the instance actually running or
other issues.
See ganeti(7) for a description of --submit and other common
options.
GROW-DISK¶
Grows an instance’s disk. This is only possible for instances having a
plain, drbd, file, sharedfile, rbd or ext disk template. For the ext
template to work, the ExtStorage provider should also support growing.
This means having a grow script that actually grows the volume of
the external shared storage.
Note that this command only change the block device size; it will not grow the actual filesystems, partitions, etc. that live on that disk. Usually, you will need to:
- use gnt-instance grow-disk
- reboot the instance (later, at a convenient time)
- use a filesystem resizer, such as ext2online(8) or xfs_growfs(8) to resize the filesystem, or use fdisk(8) to change the partition table on the disk
The disk argument is the index of the instance disk to grow. The amount argument is given as a number which can have a suffix (like the disk size in instance create); if the suffix is missing, the value will be interpreted as mebibytes.
By default, the amount value represents the desired increase in the
disk size (e.g. an amount of 1G will take a disk of size 3G to 4G). If
the optional --absolute parameter is passed, then the amount
argument doesn’t represent the delta, but instead the desired final disk
size (e.g. an amount of 8G will take a disk of size 4G to 8G).
For instances with a drbd template, note that the disk grow operation might complete on one node but fail on the other; this will leave the instance with different-sized LVs on the two nodes, but this will not create problems (except for unused space).
If you do not want gnt-instance to wait for the new disk region to be
synced, use the --no-wait-for-sync option.
See ganeti(7) for a description of --submit and other common
options.
Example (increase the first disk for instance1 by 16GiB):
# gnt-instance grow-disk instance1.example.com 0 16g
Example for increasing the disk size to a certain size:
# gnt-instance grow-disk --absolute instance1.example.com 0 32g
Also note that disk shrinking is not supported; use gnt-backup export and then gnt-backup import to reduce the disk size of an instance.
RECREATE-DISKS¶
Recreates all or a subset of disks of the given instance.
Note that this functionality should only be used for missing disks; if any of the given disks already exists, the operation will fail. While this is suboptimal, recreate-disks should hopefully not be needed in normal operation and as such the impact of this is low.
If only a subset should be recreated, any number of disk options can
be specified. It expects a disk index and an optional list of disk
parameters to change. Only size, spindles, and mode can be
changed while recreating disks. To recreate all disks while changing
parameters on a subset only, a --disk option must be given for every
disk of the instance.
Optionally the instance’s disks can be recreated on different
nodes. This can be useful if, for example, the original nodes of the
instance have gone down (and are marked offline), so we can’t recreate
on the same nodes. To do this, pass the new node(s) via -n option,
with a syntax similar to the add command. The number of nodes
passed must equal the number of nodes that the instance currently
has. Note that changing nodes is only allowed when all disks are
replaced, e.g. when no --disk option is passed.
Another method of choosing which nodes to place the instance on is by
using the specified iallocator, passing the --iallocator option.
The primary and secondary nodes will be chosen by the specified
iallocator plugin, or by the default allocator if . is specified.
See ganeti(7) for a description of --submit and other common
options.
Recovery/moving¶
FAILOVER¶
Failover will stop the instance (if running), change its primary node, and if it was originally running it will start it again (on the new primary). This works for instances with drbd template (in which case you can only fail to the secondary node) and for externally mirrored templates (sharedfile, blockdev, rbd and ext) (in which case you can fail to any other node).
If the instance’s disk template is of type sharedfile, blockdev, rbd or
ext, then you can explicitly specify the target node (which can be any
node) using the -n or --target-node option, or specify an
iallocator plugin using the -I or --iallocator option. If you
omit both, the default iallocator will be used to specify the target
node.
If the instance’s disk template is of type drbd, the target node is automatically selected as the drbd’s secondary node. Changing the secondary node is possible with a replace-disks operation.
Normally the failover will check the consistency of the disks before
failing over the instance. If you are trying to migrate instances off
a dead node, this will fail. Use the --ignore-consistency option
for this purpose. Note that this option can be dangerous as errors in
shutting down the instance will be ignored, resulting in possibly
having the instance running on two machines in parallel (on
disconnected DRBD drives). This flag requires the source node to be
marked offline first to succeed.
The --shutdown-timeout is used to specify how much time to wait
before forcing the shutdown (xm destroy in xen, killing the kvm
process, for kvm). By default two minutes are given to each instance
to stop.
If --ignore-ipolicy is given any instance policy violations occuring
during this operation are ignored.
If the --cleanup option is passed, the operation changes from
performing a failover to attempting recovery from a failed previous failover.
In this mode, Ganeti checks if the instance runs on the correct node (and
updates its configuration if not) and ensures the instance’s disks
are configured correctly.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance failover instance1.example.com
For externally mirrored templates also -n is available:
# gnt-instance failover -n node3.example.com instance1.example.com
MIGRATE¶
Migrate will move the instance to its secondary node without shutdown. As with failover, it works for instances having the drbd disk template or an externally mirrored disk template type such as sharedfile, blockdev, rbd or ext.
If the instance’s disk template is of type sharedfile, blockdev, rbd or
ext, then you can explicitly specify the target node (which can be any
node) using the -n or --target-node option, or specify an
iallocator plugin using the -I or --iallocator option. If you
omit both, the default iallocator will be used to specify the target
node. Alternatively, the default iallocator can be requested by
specifying . as the name of the plugin.
If the instance’s disk template is of type drbd, the target node is automatically selected as the drbd’s secondary node. Changing the secondary node is possible with a replace-disks operation.
The migration command needs a perfectly healthy instance for drbd instances, as we rely on the dual-master capability of drbd8 and the disks of the instance are not allowed to be degraded.
The --non-live and --migration-mode=non-live options will
switch (for the hypervisors that support it) between a “fully live”
(i.e. the interruption is as minimal as possible) migration and one in
which the instance is frozen, its state saved and transported to the
remote node, and then resumed there. This all depends on the
hypervisor support for two different methods. In any case, it is not
an error to pass this parameter (it will just be ignored if the
hypervisor doesn’t support it). The option --migration-mode=live
option will request a fully-live migration. The default, when neither
option is passed, depends on the hypervisor parameters (and can be
viewed with the gnt-cluster info command).
If the --cleanup option is passed, the operation changes from
migration to attempting recovery from a failed previous migration. In
this mode, Ganeti checks if the instance runs on the correct node (and
updates its configuration if not) and ensures the instances’ disks
are configured correctly. In this mode, the --non-live option is
ignored.
The option -f will skip the prompting for confirmation.
If --allow-failover is specified it tries to fallback to failover if
it already can determine that a migration won’t work (e.g. if the
instance is shut down). Please note that the fallback will not happen
during execution. If a migration fails during execution it still fails.
If --ignore-ipolicy is given any instance policy violations occuring
during this operation are ignored.
Normally, Ganeti will verify that the hypervisor versions on source
and target are compatible and error out if they are not. If
--ignore-hvversions is given, Ganeti will only warn in this case.
The --no-runtime-changes option forbids migrate to alter an
instance’s runtime before migrating it (eg. ballooning an instance
down because the target node doesn’t have enough available memory).
If an instance has the backend parameter always_failover set to
true, then the migration is automatically converted into a failover.
See ganeti(7) for a description of --submit and other common
options.
Example (and expected output):
# gnt-instance migrate instance1
Instance instance1 will be migrated. Note that migration
might impact the instance if anything goes wrong (e.g. due to bugs in
the hypervisor). Continue?
y/[n]/?: y
Migrating instance instance1.example.com
* checking disk consistency between source and target
* switching node node2.example.com to secondary mode
* changing into standalone mode
* changing disks into dual-master mode
* wait until resync is done
* preparing node2.example.com to accept the instance
* migrating instance to node2.example.com
* switching node node1.example.com to secondary mode
* wait until resync is done
* changing into standalone mode
* changing disks into single-master mode
* wait until resync is done
* done
#
MOVE¶
Move will move the instance to an arbitrary node in the cluster. This works only for instances having a plain or file disk template.
Note that since this operation is done via data copy, it will take a long time for big disks (similar to replace-disks for a drbd instance).
The --compress option is used to specify which compression mode
is used during the move. Valid values are ‘none’ (the default) and any
values specified in the ‘compression_tools’ cluster parameter.
The --shutdown-timeout is used to specify how much time to wait
before forcing the shutdown (e.g. xm destroy in XEN, killing the
kvm process for KVM, etc.). By default two minutes are given to each
instance to stop.
The --ignore-consistency option will make Ganeti ignore any errors
in trying to shutdown the instance on its node; useful if the
hypervisor is broken and you want to recover the data.
If --ignore-ipolicy is given any instance policy violations occuring
during this operation are ignored.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance move -n node3.example.com instance1.example.com
CHANGE-GROUP¶
This command moves an instance to another node group. The move is calculated by an iallocator, either given on the command line or as a cluster default. Note that the iallocator does only consider disk information of the default disk template, even if the instances’ disk templates differ from that.
If no specific destination groups are specified using --to, all
groups except the one containing the instance are considered.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-instance change-group -I hail --to rack2 inst1.example.com
Tags¶
ADD-TAGS¶
add-tags [–from file] {instance-name} {tag...}
Add tags to the given instance. If any of the tags contains invalid characters, the entire operation will abort.
If the --from option is given, the list of tags will be extended
with the contents of that file (each line becomes a tag). In this
case, there is not need to pass tags on the command line (if you do,
both sources will be used). A file name of - will be interpreted
as stdin.
REMOVE-TAGS¶
remove-tags [–from file] {instance-name} {tag...}
Remove tags from the given instance. If any of the tags are not existing on the node, the entire operation will abort.
If the --from option is given, the list of tags to be removed will
be extended with the contents of that file (each line becomes a tag).
In this case, there is not need to pass tags on the command line (if
you do, tags from both sources will be removed). A file name of -
will be interpreted as stdin.