NAME
vzdump - Backup Utility for VMs and Containers
SYNOPSYS
vzdump help
vzdump {<vmid>}
[OPTIONS]
Create backup.
-
<vmid>
string
-
The ID of the guest system you want to backup.
-
-all
boolean
(default=0
) -
Backup all known guest systems on this host.
-
-bwlimit
integer (0 - N)
(default=0
) -
Limit I/O bandwidth (KBytes per second).
-
-compress
(0 | 1 | gzip | lzo)
(default=0
) -
Compress dump file.
-
-dumpdir
string
-
Store resulting files to specified directory.
-
-exclude
string
-
Exclude specified guest systems (assumes --all)
-
-exclude-path
string
-
Exclude certain files/directories (shell globs).
-
-ionice
integer (0 - 8)
(default=7
) -
Set CFQ ionice priority.
-
-lockwait
integer (0 - N)
(default=180
) -
Maximal time to wait for the global lock (minutes).
-
-mailnotification
(always | failure)
(default=always
) -
Specify when to send an email
-
-mailto
string
-
Comma-separated list of email addresses that should receive email notifications.
-
-maxfiles
integer (1 - N)
(default=1
) -
Maximal number of backup files per guest system.
-
-mode
(snapshot | stop | suspend)
(default=snapshot
) -
Backup mode.
-
-node
string
-
Only run if executed on this node.
-
-pigz
integer
(default=0
) -
Use pigz instead of gzip when N>0. N=1 uses half of cores, N>1 uses N as thread count.
-
-quiet
boolean
(default=0
) -
Be quiet.
-
-remove
boolean
(default=1
) -
Remove old backup files if there are more than maxfiles backup files.
-
-script
string
-
Use specified hook script.
-
-size
integer (500 - N)
(default=1024
) -
Unused, will be removed in a future release.
-
-stdexcludes
boolean
(default=1
) -
Exclude temporary files and logs.
-
-stdout
boolean
-
Write tar to stdout, not to a file.
-
-stop
boolean
(default=0
) -
Stop runnig backup jobs on this host.
-
-stopwait
integer (0 - N)
(default=10
) -
Maximal time to wait until a guest system is stopped (minutes).
-
-storage
string
-
Store resulting file to this storage.
-
-tmpdir
string
-
Store temporary files to specified directory.
DESCRIPTION
Backups are a requirements for any sensible IT deployment, and Proxmox VE
provides a fully integrated solution, using the capabilities of each
storage and each guest system type. This allows the system
administrator to fine tune via the mode
option between consistency
of the backups and downtime of the guest system.
Proxmox VE backups are always full backups - containing the VM/CT
configuration and all data. Backups can be started via the GUI or via
the vzdump
command line tool.
Before a backup can run, a backup storage must be defined. Refer to the Storage documentation on how to add a storage. A backup storage must be a file level storage, as backups are stored as regular files. In most situations, using a NFS server is a good way to store backups. You can save those backups later to a tape drive, for off-site archiving.
Backup jobs can be scheduled so that they are executed automatically on specific days and times, for selectable nodes and guest systems. Configuration of scheduled backups is done at the Datacenter level in the GUI, which will generate a cron entry in /etc/cron.d/vzdump.
Backup modes
There are several ways to provide consistency (option mode
),
depending on the guest type.
-
stop
mode -
This mode provides the highest consistency of the backup, at the cost of a downtime in the VM operation. It works by executing an orderly shutdown of the VM, and then runs a background Qemu process to backup the VM data. After the backup is complete, the Qemu process resumes the VM to full operation mode if it was previously running.
-
suspend
mode -
This mode is provided for compatibility reason, and suspends the VM before calling the
snapshot
mode. Since suspending the VM results in a longer downtime and does not necessarily improve the data consistency, the use of thesnapshot
mode is recommended instead. -
snapshot
mode -
This mode provides the lowest operation downtime, at the cost of a small inconstancy risk. It works by performing a Proxmox VE live backup, in which data blocks are copied while the VM is running. If the guest agent is enabled (
agent: 1
) and running, it calls guest-fsfreeze-freeze and guest-fsfreeze-thaw to improve consistency.
A technical overview of the Proxmox VE live backup for QemuServer can be found online here.
|
Proxmox VE live backup provides snapshot-like semantics on any storage type. It does not require that the underlying storage supports snapshots. |
-
stop
mode -
Stop the container for the duration of the backup. This potentially results in a very long downtime.
-
suspend
mode -
This mode uses rsync to copy the container data to a temporary location (see option
--tmpdir
). Then the container is suspended and a second rsync copies changed files. After that, the container is started (resumed) again. This results in minimal downtime, but needs additional space to hold the container copy.When the container is on a local filesystem and the target storage of the backup is an NFS server, you should set
--tmpdir
to reside on a local filesystem too, as this will result in a many fold performance improvement. Use of a localtmpdir
is also required if you want to backup a local container using ACLs in suspend mode if the backup storage is an NFS server. -
snapshot
mode -
This mode uses the snapshotting facilities of the underlying storage. First, the container will be suspended to ensure data consistency. A temporary snapshot of the container’s volumes will be made and the snapshot content will be archived in a tar file. Finally, the temporary snapshot is deleted again.
|
snapshot mode requires that all backed up volumes are on a storage that
supports snapshots. Using the backup=no mountpoint option individual volumes
can be excluded from the backup (and thus this requirement). |
|
bind and device mountpoints are skipped during backup operations, like volume mountpoints with the backup option disabled. |
Backup File Names
Newer versions of vzdump encode the guest type and the backup time into the filename, for example
vzdump-lxc-105-2009_10_09-11_04_43.tar
That way it is possible to store several backup in the same
directory. The parameter maxfiles
can be used to specify the
maximum number of backups to keep.
Restore
The resulting archive files can be restored with the following programs.
-
pct restore
-
Container restore utility
-
qmrestore
-
QemuServer restore utility
For details see the corresponding manual pages.
Configuration
Global configuration is stored in /etc/vzdump.conf. The file uses a simple colon separated key/value format. Each line has the following format:
OPTION: value
Blank lines in the file are ignored, and lines starting with a # character are treated as comments and are also ignored. Values from this file are used as default, and can be overwritten on the command line.
We currently support the following options:
-
bwlimit
:integer (0 - N)
(default=0
) -
Limit I/O bandwidth (KBytes per second).
-
compress
:(0 | 1 | gzip | lzo)
(default=0
) -
Compress dump file.
-
dumpdir
:string
-
Store resulting files to specified directory.
-
exclude-path
:string
-
Exclude certain files/directories (shell globs).
-
ionice
:integer (0 - 8)
(default=7
) -
Set CFQ ionice priority.
-
lockwait
:integer (0 - N)
(default=180
) -
Maximal time to wait for the global lock (minutes).
-
mailnotification
:(always | failure)
(default=always
) -
Specify when to send an email
-
mailto
:string
-
Comma-separated list of email addresses that should receive email notifications.
-
maxfiles
:integer (1 - N)
(default=1
) -
Maximal number of backup files per guest system.
-
mode
:(snapshot | stop | suspend)
(default=snapshot
) -
Backup mode.
-
pigz
:integer
(default=0
) -
Use pigz instead of gzip when N>0. N=1 uses half of cores, N>1 uses N as thread count.
-
remove
:boolean
(default=1
) -
Remove old backup files if there are more than maxfiles backup files.
-
script
:string
-
Use specified hook script.
-
stdexcludes
:boolean
(default=1
) -
Exclude temporary files and logs.
-
stopwait
:integer (0 - N)
(default=10
) -
Maximal time to wait until a guest system is stopped (minutes).
-
storage
:string
-
Store resulting file to this storage.
-
tmpdir
:string
-
Store temporary files to specified directory.
tmpdir: /mnt/fast_local_disk
storage: my_backup_storage
mode: snapshot
bwlimit: 10000
Hook Scripts
You can specify a hook script with option --script
. This script is
called at various phases of the backup process, with parameters
accordingly set. You can find an example in the documentation
directory (vzdump-hook-script.pl).
File Exclusions
|
this option is only available for container backups. |
vzdump skips the following files by default (disable with the option
--stdexcludes 0
)
/tmp/?*
/var/tmp/?*
/var/run/?*pid
You can also manually specify (additional) exclude paths, for example:
# vzdump 777 --exclude-path /tmp/ --exclude-path '/var/foo*'
(only excludes tmp directories)
Configuration files are also stored inside the backup archive
(in ./etc/vzdump/
) and will be correctly restored.
Examples
Simply dump guest 777 - no snapshot, just archive the guest private area and configuration files to the default dump directory (usually /var/lib/vz/dump/).
# vzdump 777
Use rsync and suspend/resume to create a snapshot (minimal downtime).
# vzdump 777 --mode suspend
Backup all guest systems and send notification mails to root and admin.
# vzdump --all --mode suspend --mailto root --mailto admin
Use snapshot mode (no downtime) and non-default dump directory.
# vzdump 777 --dumpdir /mnt/backup --mode snapshot
Backup more than one guest (selectively)
# vzdump 101 102 103 --mailto root
Backup all guests excluding 101 and 102
# vzdump --mode suspend --exclude 101,102
Restore a container to a new CT 600
# pct restore 600 /mnt/backup/vzdump-lxc-777.tar
Restore a QemuServer VM to VM 601
# qmrestore /mnt/backup/vzdump-qemu-888.vma 601
Clone an existing container 101 to a new container 300 with a 4GB root file system, using pipes
# vzdump 101 --stdout | pct restore --rootfs 4 300 -
Copyright and Disclaimer
Copyright © 2007-2016 Proxmox Server Solutions GmbH
This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with this program. If not, see http://www.gnu.org/licenses/