ifdef::manvolnum[]
vzdump(1)
=========
-include::attributes.txt[]
:pve-toplevel:
NAME
ifndef::manvolnum[]
Backup and Restore
==================
-include::attributes.txt[]
-endif::manvolnum[]
-ifdef::wiki[]
:pve-toplevel:
-endif::wiki[]
+endif::manvolnum[]
-Backups are a requirements for any sensible IT deployment, and {pve}
+Backups are a requirement for any sensible IT deployment, and {pve}
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
`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.
+of a short 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 started, the VM goes to full
+operation mode if it was previously running. Consistency is guaranteed
+by using the live backup feature.
`suspend` mode::
A technical overview of the Proxmox VE live backup for QemuServer can
be found online
-https://git.proxmox.com/?p=pve-qemu-kvm.git;a=blob;f=backup.txt[here].
+https://git.proxmox.com/?p=pve-qemu.git;a=blob_plain;f=backup.txt[here].
NOTE: Proxmox VE live backup provides snapshot-like semantics on any
storage type. It does not require that the underlying storage supports
-snapshots.
+snapshots. Also please note that since the backups are done via
+a background Qemu process, a stopped VM will appear as running for a
+short amount of time while the VM disks are being read by Qemu.
+However the VM itself is not booted, only its disk(s) are read.
.Backup modes for Containers:
additional space to hold the container copy.
+
When the container is on a local file system and the target storage of
-the backup is an NFS server, you should set `--tmpdir` to reside on a
+the backup is an NFS/CIFS server, you should set `--tmpdir` to reside on a
local file system too, as this will result in a many fold performance
improvement. Use of a local `tmpdir` is also required if you want to
backup a local container using ACLs in suspend mode if the backup
supports snapshots. Using the `backup=no` mount point option individual volumes
can be excluded from the backup (and thus this requirement).
-NOTE: bind and device mount points are skipped during backup operations, like
-volume mount points with the backup option disabled.
-
+// see PVE::VZDump::LXC::prepare()
+NOTE: By default additional mount points besides the Root Disk mount point are
+not included in backups. For volume mount points you can set the *Backup* option
+to include the mount point in the backup. Device and bind mounts are never
+backed up as their content is managed outside the {pve} storage library.
Backup File Names
-----------------
directory. The parameter `maxfiles` can be used to specify the
maximum number of backups to keep.
+[[vzdump_restore]]
Restore
-------
-The resulting archive files can be restored with the following programs.
+A backup archive can be restored through the {pve} web GUI or through the
+following CLI tools:
`pct restore`:: Container restore utility
-`qmrestore`:: QemuServer restore utility
+`qmrestore`:: Virtual Machine restore utility
For details see the corresponding manual pages.
+Bandwidth Limit
+~~~~~~~~~~~~~~~
+
+Restoring one or more big backups may need a lot of resources, especially
+storage bandwidth for both reading from the backup storage and writing to
+the target storage. This can negatively effect other virtual guest as access
+to storage can get congested.
+
+To avoid this you can set bandwidth limits for a backup job. {pve}
+implements two kinds of limits for restoring and archive:
+
+* per-restore limit: denotes the maximal amount of bandwidth for
+ reading from a backup archive
+
+* per-storage write limit: denotes the maximal amount of bandwidth used for
+ writing to a specific storage
+
+The read limit indirectly affects the write limit, as we cannot write more
+than we read. A smaller per-job limit will overwrite a bigger per-storage
+limit. A bigger per-job limit will only overwrite the per-storage limit if
+you have `Data.Allocate' permissions on the affected storage.
+
+You can use the `--bwlimit <integer>` option from the restore CLI commands
+to set up a restore job specific bandwidth limit. Kibit/s is used as unit
+for the limit, this means passing `10240' will limit the read speed of the
+backup to 10 MiB/s, ensuring that the rest of the possible storage bandwidth
+is available for the already running virtual guests, and thus the backup
+does not impact their operations.
+
+NOTE: You can use `0` for the `bwlimit` parameter to disable all limits for
+a specific restore job. This can be helpful if you need to restore a very
+important virtual guest as fast as possible. (Needs `Data.Allocate'
+permissions on storage)
+
+Most times your storage's generally available bandwidth stays the same over
+time, thus we implemented the possibility to set a default bandwidth limit
+per configured storage, this can be done with:
+
+----
+# pvesm set STORAGEID --bwlimit KIBs
+----
+
+
Configuration
-------------
projects / pve-docs.git / blobdiff