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 SYNOPSYS
  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 storage
  30 and each guest system type. This allows the system administrator to fine tune via
  31 the `mode` option between consistency of the backups and downtime of the guest
  32 system. Proxmox VE backups are always full backups - containing the VM/CT
  33 configuration and all data.
  34 Backups can be started via the GUI or via the `vzdump` command line tool.
  35
  36 .Backup Storage
  37
  38 Before a backup can run, a backup storage must be defined.
  39 Refer to the Storage documentation on how to add a storage. A backup storage
  40 must be a file level storage, as backups are stored as regular files.
  41 In most situations, using a NFS server is a good way to store backups.
  42 You can save those backups later to a tape drive, for off-site archive.
  43
  44 .Scheduled Backup
  45
  46 Backup jobs can be scheduled so that they are executed automatically on
  47  specific days and times, for selectable nodes and guest systems.
  48 Configuration of scheduled backups is done at the Datacenter level in the GUI,
  49 which will generate a cron entry in /etc/cron.d/vzdump.
  50
  51 Backup modes
  52 ------------
  53 There are several ways to provide consistency (option `mode`),
  54 depending on the guest type.
  55
  56 .Backup modes for VMs:
  57
  58 `stop` mode::
  59 This mode provides the highest consistency of the backup, at the
  60 cost of a downtime in the VM operation.
  61 It works by executing an orderly shutdown of the VM, and then runs a background
  62 Qemu process to backup the VM data. After the backup is complete, the
  63 Qemu process resumes the VM to full operation mode if it was previously running.
  64
  65 `suspend` mode::
  66
  67 This mode is provided for compatibility reason, and suspends the VM before
  68 calling the `snapshot` mode. Since suspending the VM results in a longer
  69 downtime and does not necessarily improve the data consistency,
  70 the use of the `snapshot` mode is recommended instead.
  71
  72 `snapshot` mode::
  73
  74 This mode provides the lowest operation downtime, at the cost of a small
  75 inconstancy risk.
  76 It works by performing a Proxmox VE live backup, in which data blocks are copy
  77 while the VM is running. If the guest agent is enabled (`agent: 1`) and running,
  78 it calls 'guest-fsfreeze-freeze' and 'guest-fsfreeze-thaw' to improve
  79 consistency.
  80
  81 A technical overview of the Proxmox VE live backup for QemuServer can
  82 be found online
  83 https://git.proxmox.com/?p=pve-qemu-kvm.git;a=blob;f=backup.txt[here].
  84
  85 NOTE: For VMs, this _snapshot_ mode relates to the fact that the backup is
  86 performed while the VM is running. This has here nothing to do with file systems
  87 snapshots and can be operated on any kind of storage.
  88
  89 .Backup modes for Containers:
  90
  91 `stop` mode::
  92
  93 Stop the container for the duration of the backup. This potentially results in
  94 a very long downtime.
  95
  96 `suspend` mode::
  97
  98 This mode uses rsync to copy the container data to a temporary
  99 location (see option `--tmpdir`). Then the container is suspended and a second
 100 rsync copies changed files. After that, the container is started (resumed)
 101 again. This results in minimal downtime, but needs additional space
 102 to hold the container copy.
 103 +
 104 When the container is on a local filesystem and the target storage of the backup
 105 is an NFS server, you should set `--tmpdir` to reside on a local filesystem too,
 106 as this will result in a many fold performance improvement.
 107 Use of a local `tmpdir` is also required if you want to backup a local container
 108 using ACLs in suspend mode if the backup storage is an NFS server.
 109
 110 `snapshot` mode::
 111
 112 This mode uses the snapshotting facilities of the underlying
 113 storage. First, the container will be suspended to ensure data consistency.
 114 A temporary snapshot of the container's volumes will be made and the
 115 snapshot content will be archived in a tar file. Finally, the temporary
 116 snapshot is deleted again.
 117
 118 NOTE: `snapshot` mode requires that all backed up volumes are on a storage that
 119 supports snapshots. Using the `backup=no` mountpoint option individual volumes
 120 can be excluded from the backup (and thus this requirement).
 121
 122 NOTE: bind and device mountpoints are skipped during backup operations, like
 123 volume mountpoints with the backup option disabled.
 124
 125
 126 Backup File Names
 127 -----------------
 128
 129 Newer versions of vzdump encode the guest type and the
 130 backup time into the filename, for example
 131
 132  vzdump-lxc-105-2009_10_09-11_04_43.tar
 133
 134 That way it is possible to store several backup in the same
 135 directory. The parameter `maxfiles` can be used to specify the
 136 maximum number of backups to keep.
 137
 138 Restore
 139 -------
 140
 141 The resulting archive files can be restored with the following programs.
 142
 143
 144 `pct restore`:: Container restore utility
 145
 146 `qmrestore`:: QemuServer restore utility
 147
 148 For details see the corresponding manual pages.
 149
 150 Configuration
 151 -------------
 152
 153 Global configuration is stored in '/etc/vzdump.conf'. The file uses a
 154 simple colon separated key/value format. Each line has the following
 155 format:
 156
 157  OPTION: value
 158
 159 Blank lines in the file are ignored, and lines starting with a '#'
 160 character are treated as comments and are also ignored. Values from
 161 this file are used as default, and can be overwritten on the command
 162 line.
 163
 164 We currently support the following options:
 165
 166 include::vzdump.conf.5-opts.adoc[]
 167
 168
 169 .Example 'vzdump.conf' Configuration
 170 ----
 171 tmpdir: /mnt/fast_local_disk
 172 storage: my_backup_storage
 173 mode: snapshot
 174 bwlimit: 10000
 175 ----
 176
 177 Hook Scripts
 178 ------------
 179
 180 You can specify a hook script with option `--script`. This script is
 181 called at various phases of the backup process, with parameters
 182 accordingly set. You can find an example in the documentation
 183 directory ('vzdump-hook-script.pl').
 184
 185 File Exclusions
 186 ---------------
 187
 188 NOTE: this option is only available for container backups.
 189
 190 'vzdump' skips the following files by default (disable with the option
 191 `--stdexcludes 0`)
 192
 193  /tmp/?*
 194  /var/tmp/?*
 195  /var/run/?*pid
 196
 197 You can also manually specify (additional) exclude paths, for example:
 198
 199  # vzdump 777 --exclude-path /tmp/ --exclude-path '/var/foo*'
 200
 201 (only excludes tmp directories)
 202
 203 Configuration files are also stored inside the backup archive
 204 (in `./etc/vzdump/`) and will be correctly restored.
 205
 206 Examples
 207 --------
 208
 209 Simply dump guest 777 - no snapshot, just archive the guest private area and
 210 configuration files to the default dump directory (usually
 211 '/var/lib/vz/dump/').
 212
 213  # vzdump 777
 214
 215 Use rsync and suspend/resume to create a snapshot (minimal downtime).
 216
 217  # vzdump 777 --mode suspend
 218
 219 Backup all guest systems and send notification mails to root and admin.
 220
 221  # vzdump --all --mode suspend --mailto root --mailto admin
 222
 223 Use snapshot mode (no downtime) and non-default dump directory.
 224
 225  # vzdump 777 --dumpdir /mnt/backup --mode snapshot
 226
 227 Backup more than one guest (selectively)
 228
 229  # vzdump 101 102 103 --mailto root
 230
 231 Backup all guests excluding 101 and 102
 232
 233  # vzdump --mode suspend --exclude 101,102
 234
 235 Restore a container to a new CT 600
 236
 237  # pct restore 600 /mnt/backup/vzdump-lxc-777.tar
 238
 239 Restore a QemuServer VM to VM 601
 240
 241  # qmrestore /mnt/backup/vzdump-qemu-888.vma 601
 242
 243 Clone an existing container 101 to a new container 300 with a 4GB root
 244 file system, using pipes
 245
 246  # vzdump 101 --stdout | pct restore --rootfs 4 300 -
 247
 248
 249 ifdef::manvolnum[]
 250 include::pve-copyright.adoc[]
 251 endif::manvolnum[]
 252