ADD

add [--readd] [{-s|--secondary-ip} secondary_ip]
[{-g|--node-group} nodegroup]
[--master-capable=yes|no] [--vm-capable=yes|no]
[--node-parameters ndparams]
{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 the password for root of the node to be able to add the node in the cluster. 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 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 reused from the cluster. Also, the drained and offline flags of the node will be cleared before re-adding it.

The --force-join option is to proceed with adding a node even if it already appears to belong to another cluster. This is used during cluster merging, for example.

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 vm_capable, master_capable and ndparams options are described in ganeti(7), and are used to set the properties of the new 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

ADD-TAGS

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.

EVACUATE

evacuate [-f] [--early-release] [--iallocator NAME | --new-secondary destination_node] [--primary-only | --secondary-only] [--early-release] {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, 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 gnt-instance failover/migration for non-DRBD instances, but for DRBD instances it's different, and usually is a slow process (it will change the primary to another node while keeping the secondary, this requiring data copies, whereas failover/migrate will only toggle the primary/secondary roles, a fast process)
• --secondary-only is equivalent to gnt-instance replace-disks in the secondary node change mode (only valid for DRBD instances)
• when neither of the above is done a combination of the two cases is run

Example:

# gnt-node evacuate -I hail node3.example.com

FAILOVER

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.

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

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

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)

csockets

Number of physical CPU sockets (if exported by hypervisor)

ctime

Creation timestamp

ctotal

Number of logical processors

custom_ndparams

Custom node parameters

dfree

Available disk space in volume group

drained

Whether node is drained

dtotal

Total disk space in volume group used for instance disk allocation

group

Node group

group.uuid

UUID of node group

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

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 a 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

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 slighly 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).

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-FIELDS

list-fields [field...]

Lists available fields for nodes.

LIST-TAGS

list-tags {nodename}

List the tags of the given node.

MIGRATE

migrate [-f] [--non-live] [--migration-mode=live|non-live] {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 and --migration-mode can be given to influence the migration type.

Example:

# gnt-node migrate node1.example.com

MODIFY

modify [-f] [--submit]
[{-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]
{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.

Example (setting the node back to online and master candidate):

# gnt-node modify --offline=no --master-candidate=yes node1.example.com

REMOVE

remove {nodename}

Removes a node from the cluster. Instances must be removed or migrated to another cluster before.

Example:

# gnt-node remove node5.example.com

REMOVE-TAGS

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.

VOLUMES

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:

node

the node name on which the volume exists

phys

the physical drive (on which the LVM physical volume lives)

vg

the volume group name

name

the logical volume name

size

the logical volume size

instance

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

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 or file.

The -o (--output) option takes a comma-separated list of output fields. The available fields and their meaning are:

node

the node name on which the volume exists

type

the type of the storage unit (currently just what is passed in via --storage-type)

name

the path/identifier of the storage unit

size

total size of the unit; for the file type see a note below

used

used space in the unit; for the file type see a note below

free

available disk space

allocatable

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

modify-storage [--allocatable=yes|no] {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

repair-storage [--ignore-consistency] {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

powercycle [--yes] [--force] {node}

This command (tries to) forcefully reboot a node. It is a command that can be used if the node environemnt 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 require that the kernel option CONFIG_MAGIC_SYSRQ is enabled.

The --yes option can be used to skip confirmation, while the --force option is needed if the target node is the master node.

POWER

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 managment 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

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.