Langue: en

Version: 24 September 2008 (ubuntu - 08/07/09)

Section: 8 (Commandes administrateur)


gnt-backup - ganeti instance import/export


gnt-backup command [ arguments... ]


The gnt-backup is used for importing and exporting instances and their configuration from a ganeti system. It is useful for backing instances up and also to migrate them between clusters.



export -n node [ --noshutdown ] instance

Exports an instance to the target node. All the instance data and its configuration will be exported under the /srv/ganeti/exports/instance directory on the target node.

The --noshutdown option will create a snapshot disk of the instance without shutting it down first. While this is faster and involves no downtime, it cannot be guaranteed that the instance data will be in a consistent state in the exported dump.


 # gnt-backup export -n


import { -n node[:secondary-node] | --iallocator name }
    [ -s disksize ] [ --swap-size disksize ] [ -m memsize ]
    [ --cpu vcpus ] [ --ip { default | none | ip-address } ]
    [ -b bridge ] [ --no-wait-for-sync ] [ --no-ip-check ]
    --src-node=source-node --src-dir=source-dir
    -t [ diskless | plain | local_raid1 | remote_raid1 | drbd ]
    [ --auto_balance AUTO_BALANCE ] instance

Imports a new instance from an export residing on source-node in source-dir. instance must be in DNS and resolve to a IP in the same network as the nodes in the cluster.

The -s option specifies the disk size for the instance, in mebibytes (defaults to 20480MiB = 20GiB). You can also use one of the suffixes m, g or t to specificy the exact the units used; these suffixes map to mebibytes, gibibytes and tebibytes.

The --swap-size option specifies the swap disk size (in mebibytes) for the instance (the one presented as /dev/sdb). The default is 4096MiB. As for the disk size, you can specify other suffixes.

The -m option specifies the memory size for the instance, in mebibytes (defaults to 128 MiB). Again, you can use other suffixes (e.g. 2g).

The -b option specifies the bridge to which the instance will be connected. (defaults to the cluster-wide default bridge specified at cluster intialization time).

The -t options specifies the disk layout type for the instance. The available choices are:

This creates an instance with no disks. Its useful for testing only (or other special cases).
Disk devices will be logical volumes.
Disk devices will be md raid1 arrays over two local logical volumes.
Disk devices will be md raid1 arrays with one component (so it's not actually raid1): a drbd (0.7.x) device between the instance's primary node and the node given by the second value of the --node option.
Disk devices will be drbd (version 8.x) on top of lvm volumes. They are equivalent in functionality to remote_raid1, but are recommended for new instances (if you have drbd 8.x installed).

The --iallocator option specifies the instance allocator plugin to use. 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 optional second value of the --node is used for the remote raid template type and specifies the remote node.

If you do not want gnt-backup to wait for the disk mirror to be synced, use the --no-wait-for-sync option.

Use the --cpu option to set the number of virtual CPUs.

The --auto-balance option specifies whether the memory size of the instance will be considered in cluster verify checks; in the future, it might be used for automated cluster operations, but currently it is not used anywhere else. It default to true.

To pass an IPv4 address to the hypervisor, specify the --ip option. Note that this IP address will not be used by the OS scripts and changing it later will change the address that the instance will actually use.

Ganeti will not check whether an instance's IP address is already alive if the --no-ip-check option is specified.


 # gnt-backup import -t plain -s 30 -m 512 -n \
 > \
 > --src-dir=/srv/ganeti/exports/ \


list [ --node=NODE ]

Lists the exports currently available in the default directory in all the nodes of the current cluster, or optionally only a subset of them specified using the --node option (which can be used multiple times)


 # gnt-backup list --nodes node1 --nodes node2


Report bugs to 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 commands: gnt-cluster(8) (cluster-wide commands), gnt-node(8) (node-related commands), gnt-instance(8) (instance commands), gnt-os(8) (guest OS commands). gnt-backup(8) (instance import/export commands).

Ganeti daemons: ganeti-watcher(8) (automatic instance restarter), ganeti-noded(8) (node daemon), ganeti-master(8) (the master startup script), ganeti-rapi(8) (remote API daemon).

Copyright (C) 2006, 2007 Google Inc. Permission is granted to copy, distribute and/or modify under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL.