5 include::attributes.txt[]
11 vzdump - Backup Utility for VMs and Containers
17 include::vzdump.1-synopsis.adoc[]
26 include::attributes.txt[]
32 Backups are a requirements for any sensible IT deployment, and {pve}
33 provides a fully integrated solution, using the capabilities of each
34 storage and each guest system type. This allows the system
35 administrator to fine tune via the `mode` option between consistency
36 of the backups and downtime of the guest system.
38 {pve} backups are always full backups - containing the VM/CT
39 configuration and all data. Backups can be started via the GUI or via
40 the `vzdump` command line tool.
44 Before a backup can run, a backup storage must be defined. Refer to
45 the Storage documentation on how to add a storage. A backup storage
46 must be a file level storage, as backups are stored as regular files.
47 In most situations, using a NFS server is a good way to store backups.
48 You can save those backups later to a tape drive, for off-site
53 Backup jobs can be scheduled so that they are executed automatically
54 on specific days and times, for selectable nodes and guest systems.
55 Configuration of scheduled backups is done at the Datacenter level in
56 the GUI, which will generate a cron entry in /etc/cron.d/vzdump.
61 There are several ways to provide consistency (option `mode`),
62 depending on the guest type.
64 .Backup modes for VMs:
68 This mode provides the highest consistency of the backup, at the cost
69 of a downtime in the VM operation. It works by executing an orderly
70 shutdown of the VM, and then runs a background Qemu process to backup
71 the VM data. After the backup is complete, the Qemu process resumes
72 the VM to full operation mode if it was previously running.
76 This mode is provided for compatibility reason, and suspends the VM
77 before calling the `snapshot` mode. Since suspending the VM results in
78 a longer downtime and does not necessarily improve the data
79 consistency, the use of the `snapshot` mode is recommended instead.
83 This mode provides the lowest operation downtime, at the cost of a
84 small inconstancy risk. It works by performing a Proxmox VE live
85 backup, in which data blocks are copied while the VM is running. If the
86 guest agent is enabled (`agent: 1`) and running, it calls
87 `guest-fsfreeze-freeze` and `guest-fsfreeze-thaw` to improve
90 A technical overview of the Proxmox VE live backup for QemuServer can
92 https://git.proxmox.com/?p=pve-qemu-kvm.git;a=blob;f=backup.txt[here].
94 NOTE: Proxmox VE live backup provides snapshot-like semantics on any
95 storage type. It does not require that the underlying storage supports
98 .Backup modes for Containers:
102 Stop the container for the duration of the backup. This potentially
103 results in a very long downtime.
107 This mode uses rsync to copy the container data to a temporary
108 location (see option `--tmpdir`). Then the container is suspended and
109 a second rsync copies changed files. After that, the container is
110 started (resumed) again. This results in minimal downtime, but needs
111 additional space to hold the container copy.
113 When the container is on a local file system and the target storage of
114 the backup is an NFS server, you should set `--tmpdir` to reside on a
115 local file system too, as this will result in a many fold performance
116 improvement. Use of a local `tmpdir` is also required if you want to
117 backup a local container using ACLs in suspend mode if the backup
118 storage is an NFS server.
122 This mode uses the snapshotting facilities of the underlying
123 storage. First, the container will be suspended to ensure data consistency.
124 A temporary snapshot of the container's volumes will be made and the
125 snapshot content will be archived in a tar file. Finally, the temporary
126 snapshot is deleted again.
128 NOTE: `snapshot` mode requires that all backed up volumes are on a storage that
129 supports snapshots. Using the `backup=no` mount point option individual volumes
130 can be excluded from the backup (and thus this requirement).
132 NOTE: bind and device mount points are skipped during backup operations, like
133 volume mount points with the backup option disabled.
139 Newer versions of vzdump encode the guest type and the
140 backup time into the filename, for example
142 vzdump-lxc-105-2009_10_09-11_04_43.tar
144 That way it is possible to store several backup in the same
145 directory. The parameter `maxfiles` can be used to specify the
146 maximum number of backups to keep.
151 The resulting archive files can be restored with the following programs.
154 `pct restore`:: Container restore utility
156 `qmrestore`:: QemuServer restore utility
158 For details see the corresponding manual pages.
163 Global configuration is stored in `/etc/vzdump.conf`. The file uses a
164 simple colon separated key/value format. Each line has the following
169 Blank lines in the file are ignored, and lines starting with a `#`
170 character are treated as comments and are also ignored. Values from
171 this file are used as default, and can be overwritten on the command
174 We currently support the following options:
176 include::vzdump.conf.5-opts.adoc[]
179 .Example `vzdump.conf` Configuration
181 tmpdir: /mnt/fast_local_disk
182 storage: my_backup_storage
190 You can specify a hook script with option `--script`. This script is
191 called at various phases of the backup process, with parameters
192 accordingly set. You can find an example in the documentation
193 directory (`vzdump-hook-script.pl`).
198 NOTE: this option is only available for container backups.
200 `vzdump` skips the following files by default (disable with the option
207 You can also manually specify (additional) exclude paths, for example:
209 # vzdump 777 --exclude-path /tmp/ --exclude-path '/var/foo*'
211 (only excludes tmp directories)
213 Configuration files are also stored inside the backup archive
214 (in `./etc/vzdump/`) and will be correctly restored.
219 Simply dump guest 777 - no snapshot, just archive the guest private area and
220 configuration files to the default dump directory (usually
221 `/var/lib/vz/dump/`).
225 Use rsync and suspend/resume to create a snapshot (minimal downtime).
227 # vzdump 777 --mode suspend
229 Backup all guest systems and send notification mails to root and admin.
231 # vzdump --all --mode suspend --mailto root --mailto admin
233 Use snapshot mode (no downtime) and non-default dump directory.
235 # vzdump 777 --dumpdir /mnt/backup --mode snapshot
237 Backup more than one guest (selectively)
239 # vzdump 101 102 103 --mailto root
241 Backup all guests excluding 101 and 102
243 # vzdump --mode suspend --exclude 101,102
245 Restore a container to a new CT 600
247 # pct restore 600 /mnt/backup/vzdump-lxc-777.tar
249 Restore a QemuServer VM to VM 601
251 # qmrestore /mnt/backup/vzdump-qemu-888.vma 601
253 Clone an existing container 101 to a new container 300 with a 4GB root
254 file system, using pipes
256 # vzdump 101 --stdout | pct restore --rootfs 4 300 -
260 include::pve-copyright.adoc[]