vzdump.adoc

   1 ifdef::manvolnum[]
   2 PVE({manvolnum})
   3 ================
   4 include::attributes.txt[]
   5
   6 NAME
   7 ----
   8
   9 vzdump - Backup Utility for VMs and Containers
  10
  11
  12 SYNOPSIS
  13 --------
  14
  15 include::vzdump.1-synopsis.adoc[]
  16
  17
  18 DESCRIPTION
  19 -----------
  20 endif::manvolnum[]
  21
  22 ifndef::manvolnum[]
  23 Backup and Restore
  24 ==================
  25 include::attributes.txt[]
  26 endif::manvolnum[]
  27
  28 Backups are a requirements for any sensible IT deployment, and {pve}
  29 provides a fully integrated solution, using the capabilities of each
  30 storage and each guest system type. This allows the system
  31 administrator to fine tune via the `mode` option between consistency
  32 of the backups and downtime of the guest system.
  33
  34 {pve} backups are always full backups - containing the VM/CT
  35 configuration and all data.  Backups can be started via the GUI or via
  36 the `vzdump` command line tool.
  37
  38 .Backup Storage
  39
  40 Before a backup can run, a backup storage must be defined. Refer to
  41 the Storage documentation on how to add a storage. A backup storage
  42 must be a file level storage, as backups are stored as regular files.
  43 In most situations, using a NFS server is a good way to store backups.
  44 You can save those backups later to a tape drive, for off-site
  45 archiving.
  46
  47 .Scheduled Backup
  48
  49 Backup jobs can be scheduled so that they are executed automatically
  50 on specific days and times, for selectable nodes and guest systems.
  51 Configuration of scheduled backups is done at the Datacenter level in
  52 the GUI, which will generate a cron entry in /etc/cron.d/vzdump.
  53
  54 Backup modes
  55 ------------
  56
  57 There are several ways to provide consistency (option `mode`),
  58 depending on the guest type.
  59
  60 .Backup modes for VMs:
  61
  62 `stop` mode::
  63
  64 This mode provides the highest consistency of the backup, at the cost
  65 of a downtime in the VM operation.  It works by executing an orderly
  66 shutdown of the VM, and then runs a background Qemu process to backup
  67 the VM data. After the backup is complete, the Qemu process resumes
  68 the VM to full operation mode if it was previously running.
  69
  70 `suspend` mode::
  71
  72 This mode is provided for compatibility reason, and suspends the VM
  73 before calling the `snapshot` mode. Since suspending the VM results in
  74 a longer downtime and does not necessarily improve the data
  75 consistency, the use of the `snapshot` mode is recommended instead.
  76
  77 `snapshot` mode::
  78
  79 This mode provides the lowest operation downtime, at the cost of a
  80 small inconstancy risk.  It works by performing a Proxmox VE live
  81 backup, in which data blocks are copied while the VM is running. If the
  82 guest agent is enabled (`agent: 1`) and running, it calls
  83 `guest-fsfreeze-freeze` and `guest-fsfreeze-thaw` to improve
  84 consistency.
  85
  86 A technical overview of the Proxmox VE live backup for QemuServer can
  87 be found online
  88 https://git.proxmox.com/?p=pve-qemu-kvm.git;a=blob;f=backup.txt[here].
  89
  90 NOTE: Proxmox VE live backup provides snapshot-like semantics on any
  91 storage type. It does not require that the underlying storage supports
  92 snapshots.
  93
  94 .Backup modes for Containers:
  95
  96 `stop` mode::
  97
  98 Stop the container for the duration of the backup. This potentially
  99 results in a very long downtime.
 100
 101 `suspend` mode::
 102
 103 This mode uses rsync to copy the container data to a temporary
 104 location (see option `--tmpdir`). Then the container is suspended and
 105 a second rsync copies changed files. After that, the container is
 106 started (resumed) again. This results in minimal downtime, but needs
 107 additional space to hold the container copy.
 108 +
 109 When the container is on a local file system and the target storage of
 110 the backup is an NFS server, you should set `--tmpdir` to reside on a
 111 local file system too, as this will result in a many fold performance
 112 improvement.  Use of a local `tmpdir` is also required if you want to
 113 backup a local container using ACLs in suspend mode if the backup
 114 storage is an NFS server.
 115
 116 `snapshot` mode::
 117
 118 This mode uses the snapshotting facilities of the underlying
 119 storage. First, the container will be suspended to ensure data consistency.
 120 A temporary snapshot of the container's volumes will be made and the
 121 snapshot content will be archived in a tar file. Finally, the temporary
 122 snapshot is deleted again.
 123
 124 NOTE: `snapshot` mode requires that all backed up volumes are on a storage that
 125 supports snapshots. Using the `backup=no` mount point option individual volumes
 126 can be excluded from the backup (and thus this requirement).
 127
 128 NOTE: bind and device mount points are skipped during backup operations, like
 129 volume mount points with the backup option disabled.
 130
 131
 132 Backup File Names
 133 -----------------
 134
 135 Newer versions of vzdump encode the guest type and the
 136 backup time into the filename, for example
 137
 138  vzdump-lxc-105-2009_10_09-11_04_43.tar
 139
 140 That way it is possible to store several backup in the same
 141 directory. The parameter `maxfiles` can be used to specify the
 142 maximum number of backups to keep.
 143
 144 Restore
 145 -------
 146
 147 The resulting archive files can be restored with the following programs.
 148
 149
 150 `pct restore`:: Container restore utility
 151
 152 `qmrestore`:: QemuServer restore utility
 153
 154 For details see the corresponding manual pages.
 155
 156 Configuration
 157 -------------
 158
 159 Global configuration is stored in `/etc/vzdump.conf`. The file uses a
 160 simple colon separated key/value format. Each line has the following
 161 format:
 162
 163  OPTION: value
 164
 165 Blank lines in the file are ignored, and lines starting with a `#`
 166 character are treated as comments and are also ignored. Values from
 167 this file are used as default, and can be overwritten on the command
 168 line.
 169
 170 We currently support the following options:
 171
 172 include::vzdump.conf.5-opts.adoc[]
 173
 174
 175 .Example `vzdump.conf` Configuration
 176 ----
 177 tmpdir: /mnt/fast_local_disk
 178 storage: my_backup_storage
 179 mode: snapshot
 180 bwlimit: 10000
 181 ----
 182
 183 Hook Scripts
 184 ------------
 185
 186 You can specify a hook script with option `--script`. This script is
 187 called at various phases of the backup process, with parameters
 188 accordingly set. You can find an example in the documentation
 189 directory (`vzdump-hook-script.pl`).
 190
 191 File Exclusions
 192 ---------------
 193
 194 NOTE: this option is only available for container backups.
 195
 196 `vzdump` skips the following files by default (disable with the option
 197 `--stdexcludes 0`)
 198
 199  /tmp/?*
 200  /var/tmp/?*
 201  /var/run/?*pid
 202
 203 You can also manually specify (additional) exclude paths, for example:
 204
 205  # vzdump 777 --exclude-path /tmp/ --exclude-path '/var/foo*'
 206
 207 (only excludes tmp directories)
 208
 209 Configuration files are also stored inside the backup archive
 210 (in `./etc/vzdump/`) and will be correctly restored.
 211
 212 Examples
 213 --------
 214
 215 Simply dump guest 777 - no snapshot, just archive the guest private area and
 216 configuration files to the default dump directory (usually
 217 `/var/lib/vz/dump/`).
 218
 219  # vzdump 777
 220
 221 Use rsync and suspend/resume to create a snapshot (minimal downtime).
 222
 223  # vzdump 777 --mode suspend
 224
 225 Backup all guest systems and send notification mails to root and admin.
 226
 227  # vzdump --all --mode suspend --mailto root --mailto admin
 228
 229 Use snapshot mode (no downtime) and non-default dump directory.
 230
 231  # vzdump 777 --dumpdir /mnt/backup --mode snapshot
 232
 233 Backup more than one guest (selectively)
 234
 235  # vzdump 101 102 103 --mailto root
 236
 237 Backup all guests excluding 101 and 102
 238
 239  # vzdump --mode suspend --exclude 101,102
 240
 241 Restore a container to a new CT 600
 242
 243  # pct restore 600 /mnt/backup/vzdump-lxc-777.tar
 244
 245 Restore a QemuServer VM to VM 601
 246
 247  # qmrestore /mnt/backup/vzdump-qemu-888.vma 601
 248
 249 Clone an existing container 101 to a new container 300 with a 4GB root
 250 file system, using pipes
 251
 252  # vzdump 101 --stdout | pct restore --rootfs 4 300 -
 253
 254
 255 ifdef::manvolnum[]
 256 include::pve-copyright.adoc[]
 257 endif::manvolnum[]
 258