gnt-group¶
Name¶
gnt-group - Ganeti node-group administration
Synopsis¶
gnt-group {command} [arguments...]
DESCRIPTION¶
The gnt-group command is used for node group administration in the Ganeti system.
COMMANDS¶
ADD¶
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 and their corresponding
options.
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.
The -D (--disk-parameters) option allows you to set the disk
parameters for the node group; please see the section about
gnt-cluster add in gnt-cluster(8) for more information about
disk parameters
The --ipolicy-... options specify instance policies on the node
group, and are documented in the gnt-cluster(8) man page.
See ganeti(7) for a description of --submit and other common
options.
ASSIGN-NODES¶
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.
See ganeti(7) for a description of --submit and other common
options.
MODIFY¶
Modifies some parameters from the node group.
The --node-parameters and --alloc-policy options are documented
in the add command above. --hypervisor-state as well as
--disk-state are documented in detail in ganeti(7).
The --node-parameters, --alloc-policy, -D
(--disk-parameters) options are documented in the add command
above.
The --ipolicy-... options specify instance policies on the node
group, and are documented in the gnt-cluster(8) man page.
See ganeti(7) for a description of --submit and other common
options.
REMOVE¶
Deletes the indicated node group, which must be empty. There must always be at least one group, so the last group cannot be removed.
See ganeti(7) for a description of --submit and other common
options.
LIST¶
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:
alloc_policy- Allocation policy for group
ctime- Creation timestamp
custom_diskparams- Custom disk parameters
custom_ipolicy- Custom instance policy limitations
custom_ndparams- Custom node parameters
diskparams- Disk parameters (merged)
ipolicy- Instance policy limitations (merged)
mtime- Modification timestamp
name- Group 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- Node parameters
node_cnt- Number of nodes
node_list- List of nodes
pinst_cnt- Number of primary instances
pinst_list- List of primary instances
serial_no- Group object serial number, incremented on each modification
tags- Tags
uuid- Group UUID
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.
If no group names are given, then all groups are included. Otherwise, only the named groups will be listed.
RENAME¶
Renames a given group from oldname to newname.
See ganeti(7) for a description of --submit and other common
options.
EVACUATE¶
This command will move all instances out of the given node group. Instances are placed in a new group by an iallocator, either given on the command line or as a cluster default.
If no specific destination groups are specified using --to, all
groups except the evacuated group are considered.
The moves of the individual instances are handled as separate jobs
to allow for maximal parallelism. If the --sequential option is
given, the moves of the individual instances will be executed sequentially.
This can be usefull if the link between the groups is vulnerable to
congestion. If the --force-failover option is given, no migrations
will be made. This might be necessary if the group being evacuated is
too different from the other groups in the cluster.
See ganeti(7) for a description of --submit and other common
options.
Example:
# gnt-group evacuate -I hail --to rack4 rack1
Tags¶
ADD-TAGS¶
add-tags [–from file] {group} {tag...}
Add tags to the given node group. 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] {group} {tag...}
Remove tags from the given node group. 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.
SHOW-ISPECS-CMD¶
show-ispecs-cmd [–include-defaults] [group...]
Shows the command line that can be used to recreate the given groups (or all groups, if none is given) with the same options relative to specs in the instance policies.
If --include-defaults is specified, include also the default values
(i.e. the cluster-level settings), and not only the configuration items
that a group overrides.