ADD

add
[--node-parameters=NDPARAMS]
[--alloc-policy=POLICY]
{group}

Creates a new group with the given name. The node group will be initially empty; to add nodes to it, use gnt-group assign-nodes.

The --node-parameters option allows you to set default node parameters for nodes in the group. Please see ganeti(7) for more information about supported key=value pairs.

The --alloc-policy option allows you to set an allocation policy for the group at creation time. Possible values are:

unallocable

nodes in the group should not be candidates for instance allocation, and the operation (e.g., instance creation) should fail if only groups in this state could be found to satisfy the requirements.

last_resort

nodes in the group should not be used for instance allocations, unless this would be the only way to have the operation succeed.

preferred

nodes in the group can be used freely for allocation of instances (this is the default). Note that prioritization among groups in this state will be deferred to the iallocator plugin that's being used.

ASSIGN-NODES

assign-nodes
[--force]
{group} {node...}

Assigns one or more nodes to the specified group, moving them from their original group (or groups).

By default, this command will refuse to proceed if the move would split between groups any instance that was not previously split (a split instance is an instance with a mirrored disk template, e.g. DRBD, that has the primary and secondary nodes in different node groups). You can force the operation with --force.

MODIFY

modify
[--node-parameters=NDPARAMS]
[--alloc-policy=POLICY]
{group}

Modifies some parameters from the node group.

The --node-parameters and --alloc-policy optiosn are documented in the add command above.

REMOVE

remove {group}

Deletes the indicated node group, which must be empty. There must always be at least one group, so the last group cannot be removed.

LIST

list [--no-headers] [--separator=SEPARATOR] [-v]
[-o [+]FIELD,...] [group...]

Lists all existing node groups 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 -v option activates verbose mode, which changes the display of special field states (see ganeti(7)).

The -o option takes a comma-separated list of output fields. 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.

The available fields and their meaning are:

name

the group name

uuid

the group's UUID

node_cnt

the number of nodes in the node group

node_list

the list of nodes that belong to this group

pinst_cnt

the number of primary instances in the group (i.e., the number of primary instances nodes in this group have)

pinst_list

the list of primary instances in the group

alloc_policy

the current allocation policy for the group

ctime

the creation time of the group; note that this field contains spaces and as such it's harder to parse

if this attribute is not present (e.g. when upgrading from older versions), then "N/A" will be shown instead

mtime

the last modification time of the group; note that this field contains spaces and as such it's harder to parse

serial_no

the so called 'serial number' of the group; this is a numeric field that is incremented each time the node is modified, and it can be used to detect modifications

If no group names are given, then all groups are included. Otherwise, only the named groups will be listed.

LIST-FIELDS

list-fields [field...]

List available fields for node groups.

RENAME

rename {oldname} {newname}

Renames a given group from oldname to newname.