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 'vzdump' is a utility to make consistent backups of running guest
  29 systems. It basically creates an archive of the guest private area,
  30 which also includes the guest configuration files. 'vzdump' currently
  31 supports LXC containers and QemuServer VMs. There are several ways to
  32 provide consistency (option `mode`), depending on the guest type.
  33
  34 .Backup `mode` for VMs:
  35
  36 `stop` mode::
  37
  38 This first performns a clean shutdown of the VM to make sure it is
  39 stopped. It then starts the VM in suspended mode and uses the qemu
  40 backup feature to dump all data. If the VM was running, we start
  41 (resume) it immediately after starting the qemu backup task. This
  42 keeps the downtime as low as possible.
  43
  44 `suspend` mode::
  45
  46 This mode does not really make sense for qemu. Please use snapshot
  47 mode instead.
  48
  49 `snapshot` mode::
  50
  51 This mode simply starts a qemu live backup task. If the guest agent
  52 is enabled (`agent: 1`) and running, it calls 'guest-fsfreeze-freeze'
  53 and 'guest-fsfreeze-thaw' to improve consistency.
  54
  55 A technical overview of the Proxmox VE live backup for QemuServer can
  56 be found online
  57 https://git.proxmox.com/?p=pve-qemu-kvm.git;a=blob;f=backup.txt[here].
  58
  59 NOTE: Qemu backup provides snapshots on any storage type. It does
  60 not require that the underlying storage supports snapshots.
  61
  62
  63 .Backup `mode` for Containers:
  64
  65 `stop` mode::
  66
  67 Stop the container for the duration of the backup. This potentially results in
  68 a very long downtime.
  69
  70 `suspend` mode::
  71
  72 This mode uses rsync to copy the container data to a temporary
  73 location (see option `--tmpdir`). Then the container is suspended and a second
  74 rsync copies changed files. After that, the container is started (resumed)
  75 again. This results in minimal downtime, but needs additional space
  76 to hold the container copy.
  77 +
  78 When the container is on a local filesystem and the target storage of the backup
  79 is an NFS server, you should set `--tmpdir` to reside on a local filesystem too,
  80 as this will result in a many fold performance improvement.
  81 Use of a local `tmpdir` is also required if you want to backup a local container
  82 using ACLs in suspend mode if the backup storage is an NFS server.
  83
  84 `snapshot` mode::
  85
  86 This mode uses the snapshotting facilities of the underlying
  87 storage. First, the container will be suspended to ensure data consistency.
  88 A temporary snapshot of the container's volumes will be made and the
  89 snapshot content will be archived in a tar file. Finally, the temporary
  90 snapshot is deleted again.
  91
  92 NOTE: `snapshot` mode requires that all backed up volumes are on a storage that
  93 supports snapshots. Using the `backup=no` mountpoint option individual volumes
  94 can be excluded from the backup (and thus this requirement).
  95
  96
  97 Backup File Names
  98 -----------------
  99
 100 Newer versions of vzdump encode the guest type and the
 101 backup time into the filename, for example
 102
 103  vzdump-lxc-105-2009_10_09-11_04_43.tar
 104
 105 That way it is possible to store several backup in the same
 106 directory. The parameter `maxfiles` can be used to specify the
 107 maximum number of backups to keep.
 108
 109 Restore
 110 -------
 111
 112 The resulting archive files can be restored with the following programs.
 113
 114
 115 `pct restore`:: Container restore utility
 116
 117 `qmrestore`:: QemuServer restore utility
 118
 119 For details see the corresponding manual pages.
 120
 121 Configuration
 122 -------------
 123
 124 Global configuration is stored in '/etc/vzdump.conf'. The file uses a
 125 simple colon separated key/value format. Each line has the following
 126 format:
 127
 128  OPTION: value
 129
 130 Blank lines in the file are ignored, and lines starting with a '#'
 131 character are treated as comments and are also ignored. Values from
 132 this file are used as default, and can be overwritten on the command
 133 line.
 134
 135 We currently support the following options:
 136
 137 include::vzdump.conf.5-opts.adoc[]
 138
 139
 140 .Example 'vzdump.conf' Configuration
 141 ----
 142 tmpdir: /mnt/fast_local_disk
 143 storage: my_backup_storage
 144 mode: snapshot
 145 bwlimit: 10000
 146 ----
 147
 148 Hook Scripts
 149 ------------
 150
 151 You can specify a hook script with option `--script`. This script is
 152 called at various phases of the backup process, with parameters
 153 accordingly set. You can find an example in the documentation
 154 directory ('vzdump-hook-script.pl').
 155
 156 File Exclusions
 157 ---------------
 158
 159 NOTE: this option is only available for container backups.
 160
 161 'vzdump' skips the following files by default (disable with the option
 162 `--stdexcludes 0`)
 163
 164  /var/log/?*
 165  /tmp/?*
 166  /var/tmp/?*
 167  /var/run/?*pid
 168
 169 You can also manually specify (additional) exclude paths, for example:
 170
 171  # vzdump 777 --exclude-path /tmp/ --exclude-path '/var/foo*'
 172
 173 (only excludes tmp directories)
 174
 175 Configuration files are also stored inside the backup archive
 176 (in `./etc/vzdump/`) and will be correctly restored.
 177
 178 Examples
 179 --------
 180
 181 Simply dump guest 777 - no snapshot, just archive the guest private area and
 182 configuration files to the default dump directory (usually
 183 '/var/lib/vz/dump/').
 184
 185  # vzdump 777
 186
 187 Use rsync and suspend/resume to create a snapshot (minimal downtime).
 188
 189  # vzdump 777 --mode suspend
 190
 191 Backup all guest systems and send notification mails to root and admin.
 192
 193  # vzdump --all --mode suspend --mailto root --mailto admin
 194
 195 Use snapshot mode (no downtime) and non-default dump directory.
 196
 197  # vzdump 777 --dumpdir /mnt/backup --mode snapshot
 198
 199 Backup more than one guest (selectively)
 200
 201  # vzdump 101 102 103 --mailto root
 202
 203 Backup all guests excluding 101 and 102
 204
 205  # vzdump --mode suspend --exclude 101,102
 206
 207 Restore a container to a new CT 600
 208
 209  # pct restore 600 /mnt/backup/vzdump-lxc-777.tar
 210
 211 Restore a QemuServer VM to VM 601
 212
 213  # qmrestore /mnt/backup/vzdump-qemu-888.vma 601
 214
 215 Clone an existing container 101 to a new container 300 with a 4GB root
 216 file system, using pipes
 217
 218  # vzdump 101 --stdout | pct restore --rootfs 4 300 -
 219
 220
 221 ifdef::manvolnum[]
 222 include::pve-copyright.adoc[]
 223 endif::manvolnum[]
 224