gnt-node - Node administration
gnt-node {command} [arguments...]
The gnt-node is used for managing the (physical) nodes in the Ganeti system.
add [--readd] [{-s|--secondary-ip} secondary_ip]
[{-g|--node-group} nodegroup]
[--master-capable=yes|no
] [--vm-capable=yes|no
]
[--node-parameters ndparams]
[--disk-state diskstate]
[--hypervisor-state hvstate]
[--no-node-setup]
[--verbose] | [--debug]
{nodename}
Adds the given node to the cluster.
This command is used to join a new node to the cluster. You will have to provide credentials to ssh as root to the node to be added. Forwardig of an ssh agent (the -A
option of ssh) works, if an appropriate authorized key is set up on the node to be added. If the other node allows password authentication for root, another way of providing credentials is to provide the root password once asked for it. The command needs to be run on the Ganeti master.
Note that the command is potentially destructive, as it will forcibly join the specified host to the cluster, not paying attention to its current status (it could be already in a cluster, etc.)
The -s (--secondary-ip)
is used in dual-home clusters and specifies the new node's IP in the secondary network. See the discussion in gnt-cluster(8) for more information.
In case you're readding a node after hardware failure, you can use the --readd
parameter. In this case, you don't need to pass the secondary IP again, it will be reused from the cluster. Also, the drained and offline flags of the node will be cleared before re-adding it. Note that even for readded nodes, a new SSH key is generated and distributed and previous Ganeti keys are removed from the machine.
The -g (--node-group)
option is used to add the new node into a specific node group, specified by UUID or name. If only one node group exists you can skip this option, otherwise it's mandatory.
The --no-node-setup
option that used to prevent Ganeti from performing the initial SSH setup on the new node is no longer valid. Instead, Ganeti consideres the modify ssh setup
configuration parameter (which is set using --no-ssh-init
during cluster initialization) to determine whether or not to do the SSH setup on a new node or not. If this parameter is set to False
, Ganeti will not touch the SSH keys or the authorized_keys
file of the node at all. Using this option, it lies in the administrators responsibility to ensure SSH connectivity between the hosts by other means.
The vm_capable
, master_capable
, ndparams
, diskstate
and hvstate
options are described in ganeti(7), and are used to set the properties of the new node.
The command performs some operations that change the state of the master and the new node, like copying certificates and starting the node daemon on the new node, or updating /etc/hosts
on the master node. If the command fails at a later stage, it doesn't undo such changes. This should not be a problem, as a successful run of gnt-node add
will bring everything back in sync.
If the node was previously part of another cluster and still has daemons running, the node-cleanup
tool can be run on the machine to be added to clean remains of the previous cluster from the node.
The options --verbose
and --debug
control the log level of the operation, in particular the one of the underlying SSH calls that Ganeti makes when adding a node.
Example:
# gnt-node add node5.example.com
# gnt-node add -s 192.0.2.5 node5.example.com
# gnt-node add -g group2 -s 192.0.2.9 node9.group2.example.com
evacuate [-f] [--early-release] [--submit] [--print-jobid]
[{-I|--iallocator} NAME | {-n|--new-secondary} destination_node]
[--ignore-soft-errors]
[{-p|--primary-only} | {-s|--secondary-only} ]
{node}
This command will move instances away from the given node. If --primary-only
is given, only primary instances are evacuated, with --secondary-only
only secondaries. If neither is given, all instances are evacuated. It works only for instances having a drbd disk template.
The new location for the instances can be specified in two ways:
as a single node for all instances, via the -n (--new-secondary)
option
or via the -I (--iallocator)
option, giving a script name as parameter (or .
to use the default allocator), so each instance will be in turn placed on the (per the script) optimal node
The --early-release
changes the code so that the old storage on node being evacuated is removed early (before the resync is completed) and the internal Ganeti locks are also released for both the current secondary and the new secondary, 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).
Note that this command is equivalent to using per-instance commands for each affected instance individually:
--primary-only
is equivalent to performing gnt-instance migrate
for every primary instance running on the node that can be migrated and gnt-instance failover
for every primary instance that cannot be migrated.--secondary-only
is equivalent to gnt-instance replace-disks
in secondary node change mode (--new-secondary
) for every DRBD instance that the node is a secondary for.Note that the iallocator currently only considers disk information of the default disk template, even if the instance's disk templates differ from that.
The --ignore-soft-errors
option is passed through to the allocator.
See ganeti(7) for a description of --submit
and other common options.
Example:
# gnt-node evacuate -I hail node3.example.com
Note that, due to an issue with the iallocator interface, evacuation of all instances at once is not yet implemented. Full evacuation can currently be achieved by sequentially evacuating primaries and secondaries.
# gnt-node evacuate -p node3.example.com
# gnt-node evacuate -s node3.example.com
failover [-f] [--ignore-consistency] {node}
This command will fail over all instances having the given node as primary to their secondary nodes. This works only for instances having a drbd disk template.
Note that failover will stop any running instances on the given node and restart them again on the new primary. See also FAILOVER in gnt-instance(8).
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.
Example:
# gnt-node failover node1.example.com
info [node...]
Show detailed information about the nodes in the cluster. If you don't give any arguments, all nodes will be shows, otherwise the output will be restricted to the given names.
list
[--no-headers] [--separator=SEPARATOR]
[--units=UNITS] [-v] [{-o|--output} [+]FIELD,...]
[--filter]
[node...]
Lists the nodes in the cluster.
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.
Queries of nodes will be done in parallel with any running jobs. This might give inconsistent results for the free disk/memory.
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:
bootid
Random UUID renewed for each system reboot, can be used for detecting reboots by tracking changes
cnodes
Number of NUMA domains on node (if exported by hypervisor)
cnos
Number of logical processors used by the node OS (dom0 for Xen)
csockets
Number of physical CPU sockets (if exported by hypervisor)
ctime
Creation timestamp
ctotal
Number of logical processors
custom_hv_state
Custom static hypervisor state
custom_ndparams
Custom node parameters
dfree
Available storage space in storage unit
disk_state
Disk state
drained
Whether node is drained
dtotal
Total storage space in storage unit used for instance disk allocation
group
Node group
group.uuid
UUID of node group
hv_state
Static hypervisor state for default hypervisor only
master
Whether node is master
master_candidate
Whether node is a master candidate
master_capable
Whether node can become a master candidate
mfree
Memory available for instance allocations
mnode
Amount of memory used by node (dom0 for Xen)
mtime
Modification timestamp
mtotal
Total amount of memory of physical machine
name
Node name
ndp/cpu_speed
The "cpu_speed" node parameter
ndp/exclusive_storage
The "exclusive_storage" node parameter
ndp/oob_program
The "oob_program" node parameter
ndp/ovs
The "ovs" node parameter
ndp/ovs_link
The "ovs_link" node parameter
ndp/ovs_name
The "ovs_name" node parameter
ndp/spindle_count
The "spindle_count" node parameter
ndp/ssh_port
The "ssh_port" node parameter
ndparams
Merged node parameters
offline
Whether node is marked offline
pinst_cnt
Number of instances with this node as primary
pinst_list
List of instances with this node as primary
pip
Primary IP address
powered
Whether node is thought to be powered on
role
Node role; "M" for master, "C" for master candidate, "R" for regular, "D" for drained, "O" for offline
serial_no
Node object serial number, incremented on each modification
sinst_cnt
Number of instances with this node as secondary
sinst_list
List of instances with this node as secondary
sip
Secondary IP address
spfree
Available spindles in volume group (exclusive storage only)
sptotal
Total spindles in volume group (exclusive storage only)
tags
Tags
uuid
Node UUID
vm_capable
Whether node can host instances
If the value of the option starts with the character +
, the new fields 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.
Note that some of these fields are known from the configuration of the cluster (e.g. name
, pinst
, sinst
, pip
, sip
) and thus the master does not need to contact the node for this data (making the listing fast if only fields from this set are selected), whereas the other fields are "live" fields and require a query to the cluster nodes.
Depending on the virtualization type and implementation details, the mtotal
, mnode
and mfree
fields may have slightly varying meanings. For example, some solutions share the node memory with the pool of memory used for instances (KVM), whereas others have separate memory for the node and for the instances (Xen).
Note that the field 'dtotal' and 'dfree' refer to the storage type that is defined by the default disk template. The default disk template is the first on in the list of cluster-wide enabled disk templates and can be set with gnt-cluster modify
. Currently, only the disk templates 'plain', 'drbd', 'file', and 'sharedfile' support storage reporting, for all others '0' is displayed.
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-node list -F master_candidate
).
If no node names are given, then all nodes are queried. Otherwise, only the given nodes will be listed.
list-drbd [--no-headers] [--separator=SEPARATOR] node
Lists the mapping of DRBD minors for a given node. This outputs a static list of fields (it doesn't accept the --output
option), as follows:
Node
The (full) name of the node we are querying
Minor
The DRBD minor
Instance
The instance the DRBD minor belongs to
Disk
The disk index that the DRBD minor belongs to
Role
Either primary
or secondary
, denoting the role of the node for the instance (note: this is not the live status of the DRBD device, but the configuration value)
PeerNode
The node that the minor is connected to on the other end
This command can be used as a reverse lookup (from node and minor) to a given instance, which can be useful when debugging DRBD issues.
Note that this command queries Ganeti via ganeti-confd(8), so it won't be available if support for confd
has not been enabled at build time; furthermore, in Ganeti 2.6 this is only available via the Haskell version of confd (again selected at build time).
list-fields [field...]
Lists available fields for nodes.
migrate [-f] [--non-live] [--migration-mode=live|non-live]
[--ignore-ipolicy] [--submit] [--print-jobid] {node}
This command will migrate all instances having the given node as primary to their secondary nodes. This works only for instances having a drbd disk template.
As for the gnt-instance migrate command, the options --no-live
, --migration-mode
and --no-runtime-changes
can be given to influence the migration type.
If --ignore-ipolicy
is given any instance policy violations occurring during this operation are ignored.
See ganeti(7) for a description of --submit
and other common options.
Example:
# gnt-node migrate node1.example.com
modify [-f] [--submit] [--print-jobid]
[{-C|--master-candidate} yes|no
]
[{-D|--drained} yes|no
] [{-O|--offline} yes|no
]
[--master-capable=yes|no
] [--vm-capable=yes|no
] [--auto-promote]
[{-s|--secondary-ip} secondary_ip]
[--node-parameters ndparams]
[--node-powered=yes|no
]
[--hypervisor-state hvstate]
[--disk-state diskstate]
[--verbose] [--debug]
{node}
This command changes the role of the node. Each options takes either a literal yes or no, and only one option should be given as yes. The meaning of the roles and flags are described in the manpage ganeti(7).
The option --node-powered
can be used to modify state-of-record if it doesn't reflect the reality anymore.
In case a node is demoted from the master candidate role, the operation will be refused unless you pass the --auto-promote
option. This option will cause the operation to lock all cluster nodes (thus it will not be able to run in parallel with most other jobs), but it allows automated maintenance of the cluster candidate pool. If locking all cluster node is too expensive, another option is to promote manually another node to master candidate before demoting the current one.
Example (setting a node offline, which will demote it from master candidate role if is in that role):
# gnt-node modify --offline=yes node1.example.com
The -s (--secondary-ip)
option can be used to change the node's secondary ip. No drbd instances can be running on the node, while this operation is taking place. Remember that the secondary ip must be reachable from the master secondary ip, when being changed, so be sure that the node has the new IP already configured and active. In order to convert a cluster from single homed to multi-homed or vice versa --force
is needed as well, and the target node for the first change must be the master.
The options --verbose
and --debug
control the log level of the operation, in particular the one of the underlying SSH calls that Ganeti makes when modifying some parameters a node (e.g. promoting or demoting a node to or from 'master candidate' status).
See ganeti(7) for a description of --submit
and other common options.
Example (setting the node back to online and master candidate):
# gnt-node modify --offline=no --master-candidate=yes node1.example.com
remove [--verbose] [--debug] {nodename}
Removes a node from the cluster. Instances must be removed or migrated to another cluster before.
The options --verbose
and --debug
control the log level of the operation, in particular the one of the underlying SSH calls that Ganeti makes when removing a node.
Example:
# gnt-node remove node5.example.com
volumes [--no-headers] [--human-readable]
[--separator=SEPARATOR] [{-o|--output} FIELDS]
[node...]
Lists all logical volumes and their physical disks from the node(s) provided.
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 -o (--output)
option takes a comma-separated list of output fields. The available fields and their meaning are:
the node name on which the volume exists
the physical drive (on which the LVM physical volume lives)
the volume group name
the logical volume name
the logical volume size
The name of the instance to which this volume belongs, or (in case it's an orphan volume) the character "-"
Example:
# gnt-node volumes node5.example.com
Node PhysDev VG Name Size Instance
node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11000.meta 128 instance1.example.com
node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11001.data 256 instance1.example.com
list-storage [--no-headers] [--human-readable]
[--separator=SEPARATOR] [--storage-type=STORAGE_TYPE]
[{-o|--output} FIELDS]
[node...]
Lists the available storage units and their details for the given node(s).
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 --storage-type
option can be used to choose a storage unit type. Possible choices are lvm-pv, lvm-vg, file, sharedfile and gluster.
The -o (--output)
option takes a comma-separated list of output fields. The available fields and their meaning are:
the node name on which the volume exists
the type of the storage unit (currently just what is passed in via --storage-type
)
the path/identifier of the storage unit
total size of the unit; for the file type see a note below
used space in the unit; for the file type see a note below
available disk space
whether we the unit is available for allocation (only lvm-pv can change this setting, the other types always report true)
Note that for the "file" type, the total disk space might not equal to the sum of used and free, due to the method Ganeti uses to compute each of them. The total and free values are computed as the total and free space values for the filesystem to which the directory belongs, but the used space is computed from the used space under that directory only, which might not be necessarily the root of the filesystem, and as such there could be files outside the file storage directory using disk space and causing a mismatch in the values.
Example:
node1# gnt-node list-storage node2
Node Type Name Size Used Free Allocatable
node2 lvm-pv /dev/sda7 673.8G 1.5G 672.3G Y
node2 lvm-pv /dev/sdb1 698.6G 0M 698.6G Y
modify-storage [--allocatable={yes|no}] [--submit] [--print-jobid]
{node} {storage-type} {volume-name}
Modifies storage volumes on a node. Only LVM physical volumes can be modified at the moment. They have a storage type of "lvm-pv".
Example:
# gnt-node modify-storage --allocatable no node5.example.com lvm-pv /dev/sdb1
repair-storage [--ignore-consistency] ]--submit]
{node} {storage-type} {volume-name}
Repairs a storage volume on a node. Only LVM volume groups can be repaired at this time. They have the storage type "lvm-vg".
On LVM volume groups, repair-storage runs vgreduce --removemissing
.
Caution: Running this command can lead to data loss. Use it with care.
The --ignore-consistency
option will ignore any inconsistent disks (on the nodes paired with this one). Use of this option is most likely to lead to data-loss.
Example:
# gnt-node repair-storage node5.example.com lvm-vg xenvg
powercycle [--yes] [--force] [--submit] [--print-jobid] {node}
This command (tries to) forcefully reboot a node. It is a command that can be used if the node environment is broken, such that the admin can no longer login over SSH, but the Ganeti node daemon is still working.
Note that this command is not guaranteed to work; it depends on the hypervisor how effective is the reboot attempt. For Linux, this command requires the kernel option CONFIG_MAGIC_SYSRQ
to be enabled.
The --yes
option can be used to skip confirmation, while the --force
option is needed if the target node is the master node.
See ganeti(7) for a description of --submit
and other common options.
power [--force
] [--ignore-status
] [--all
] [--power-delay
] on|off|cycle|status [nodes]
This command calls out to out-of-band management to change the power state of given node. With status
you get the power status as reported by the out-of-band management script.
Note that this command will only work if the out-of-band functionality is configured and enabled on the cluster. If this is not the case, please use the powercycle command above.
Using --force
you skip the confirmation to do the operation. Currently this only has effect on off
and cycle
. On those two you can not operate on the master. However, the command will provide you with the command to invoke to operate on the master nerver-mind. This is considered harmful and Ganeti does not support the use of it.
Providing --ignore-status
will ignore the offline=N state of a node and continue with power off.
--power-delay
specifies the time in seconds (factions allowed) waited between powering on the next node. This is by default 2 seconds but can increased if needed with this option.
nodes are optional. If not provided it will call out for every node in the cluster. Except for the off
and cycle
command where you've to explicit use --all
to select all.
health [nodes]
This command calls out to out-of-band management to ask for the health status of all or given nodes. The health contains the node name and then the items element with their status in a item=status
manner. Where item
is script specific and status
can be one of OK
, WARNING
, CRITICAL
or UNKNOWN
. Items with status WARNING
or CRITICAL
are logged and annotated in the command line output.
restricted-command [-M] [--sync]
{ -g group command | command nodes... }
Executes a restricted command on the specified nodes. Restricted commands are not arbitrary, but must reside in /etc/ganeti/restricted-commands
on a node, either as a regular file or as a symlink. The directory must be owned by root and not be world- or group-writable. If a command fails verification or otherwise fails to start, the node daemon log must be consulted for more detailed information.
Example for running a command on two nodes:
# gnt-node restricted-command mycommand \
node1.example.com node2.example.com
The -g
option can be used to run a command only on a specific node group, e.g.:
# gnt-node restricted-command -g default mycommand
The -M
option can be used to prepend the node name to all command output lines. --sync
forces the opcode to acquire the node lock(s) in exclusive mode.
repair-command { --input input } command node
Executes a repair command. Repair commands reside in /etc/ganeti/node-repair-commands
on a node, either as a regular file or as a symlink. The directory must be owned by root and not be world- or group-writable. If a command fails verification or otherwise fails to start, the node daemon log must be consulted for more detailed information.
Example for running a command:
# gnt-node repair-command --input "input string" \
mycommand node.example.com
add-tags [--from file] {nodename} {tag...}
Add tags to the given node. 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.
list-tags {nodename}
List the tags of the given node.
remove-tags [--from file] {nodename} {tag...}
Remove tags from the given node. 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.
Report bugs to project website or contact the developers using the Ganeti mailing list.
Ganeti overview and specifications: ganeti(7) (general overview), ganeti-os-interface(7) (guest OS definitions), ganeti-extstorage-interface(7) (external storage providers).
Ganeti commands: gnt-cluster(8) (cluster-wide commands), gnt-job(8) (job-related commands), gnt-node(8) (node-related commands), gnt-instance(8) (instance commands), gnt-os(8) (guest OS commands), gnt-storage(8) (storage commands), gnt-group(8) (node group commands), gnt-backup(8) (instance import/export commands), gnt-debug(8) (debug commands).
Ganeti daemons: ganeti-watcher(8) (automatic instance restarter), ganeti-cleaner(8) (job queue cleaner), ganeti-noded(8) (node daemon), ganeti-rapi(8) (remote API daemon).
Ganeti htools: htools(1) (generic binary), hbal(1) (cluster balancer), hspace(1) (capacity calculation), hail(1) (IAllocator plugin), hscan(1) (data gatherer from remote clusters), hinfo(1) (cluster information printer), mon-collector(7) (data collectors interface).
Copyright (C) 2006-2015 Google Inc. All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.