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@ -26,86 +26,92 @@ include::attributes.txt[]
endif::manvolnum[] endif::manvolnum[]
Backups are a requirements for any sensible IT deployment, and {pve} Backups are a requirements for any sensible IT deployment, and {pve}
provides a fully integrated solution, using the capabilities of each storage provides a fully integrated solution, using the capabilities of each
and each guest system type. This allows the system administrator to fine tune via storage and each guest system type. This allows the system
the `mode` option between consistency of the backups and downtime of the guest administrator to fine tune via the `mode` option between consistency
system. Proxmox VE backups are always full backups - containing the VM/CT of the backups and downtime of the guest system.
configuration and all data.
Backups can be started via the GUI or via the `vzdump` command line tool. {pve} backups are always full backups - containing the VM/CT
configuration and all data. Backups can be started via the GUI or via
the `vzdump` command line tool.
.Backup Storage .Backup Storage
Before a backup can run, a backup storage must be defined. Before a backup can run, a backup storage must be defined. Refer to
Refer to the Storage documentation on how to add a storage. A backup storage the Storage documentation on how to add a storage. A backup storage
must be a file level storage, as backups are stored as regular files. must be a file level storage, as backups are stored as regular files.
In most situations, using a NFS server is a good way to store backups. In most situations, using a NFS server is a good way to store backups.
You can save those backups later to a tape drive, for off-site archive. You can save those backups later to a tape drive, for off-site
archiving.
.Scheduled Backup .Scheduled Backup
Backup jobs can be scheduled so that they are executed automatically on Backup jobs can be scheduled so that they are executed automatically
specific days and times, for selectable nodes and guest systems. on specific days and times, for selectable nodes and guest systems.
Configuration of scheduled backups is done at the Datacenter level in the GUI, Configuration of scheduled backups is done at the Datacenter level in
which will generate a cron entry in /etc/cron.d/vzdump. the GUI, which will generate a cron entry in /etc/cron.d/vzdump.
Backup modes Backup modes
------------ ------------
There are several ways to provide consistency (option `mode`), There are several ways to provide consistency (option `mode`),
depending on the guest type. depending on the guest type.
.Backup modes for VMs: .Backup modes for VMs:
`stop` mode:: `stop` mode::
This mode provides the highest consistency of the backup, at the
cost of a downtime in the VM operation. This mode provides the highest consistency of the backup, at the cost
It works by executing an orderly shutdown of the VM, and then runs a background of a downtime in the VM operation. It works by executing an orderly
Qemu process to backup the VM data. After the backup is complete, the shutdown of the VM, and then runs a background Qemu process to backup
Qemu process resumes the VM to full operation mode if it was previously running. the VM data. After the backup is complete, the Qemu process resumes
the VM to full operation mode if it was previously running.
`suspend` mode:: `suspend` mode::
This mode is provided for compatibility reason, and suspends the VM before This mode is provided for compatibility reason, and suspends the VM
calling the `snapshot` mode. Since suspending the VM results in a longer before calling the `snapshot` mode. Since suspending the VM results in
downtime and does not necessarily improve the data consistency, a longer downtime and does not necessarily improve the data
the use of the `snapshot` mode is recommended instead. consistency, the use of the `snapshot` mode is recommended instead.
`snapshot` mode:: `snapshot` mode::
This mode provides the lowest operation downtime, at the cost of a small This mode provides the lowest operation downtime, at the cost of a
inconstancy risk. small inconstancy risk. It works by performing a Proxmox VE live
It works by performing a Proxmox VE live backup, in which data blocks are copy backup, in which data blocks are copied while the VM is running. If the
while the VM is running. If the guest agent is enabled (`agent: 1`) and running, guest agent is enabled (`agent: 1`) and running, it calls
it calls 'guest-fsfreeze-freeze' and 'guest-fsfreeze-thaw' to improve 'guest-fsfreeze-freeze' and 'guest-fsfreeze-thaw' to improve
consistency. consistency.
A technical overview of the Proxmox VE live backup for QemuServer can A technical overview of the Proxmox VE live backup for QemuServer can
be found online 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-kvm.git;a=blob;f=backup.txt[here].
NOTE: For VMs, this _snapshot_ mode relates to the fact that the backup is NOTE: Proxmox VE live backup provides snapshot-like semantics on any
performed while the VM is running. This has here nothing to do with file systems storage type. It does not require that the underlying storage supports
snapshots and can be operated on any kind of storage. snapshots.
.Backup modes for Containers: .Backup modes for Containers:
`stop` mode:: `stop` mode::
Stop the container for the duration of the backup. This potentially results in Stop the container for the duration of the backup. This potentially
a very long downtime. results in a very long downtime.
`suspend` mode:: `suspend` mode::
This mode uses rsync to copy the container data to a temporary This mode uses rsync to copy the container data to a temporary
location (see option `--tmpdir`). Then the container is suspended and a second location (see option `--tmpdir`). Then the container is suspended and
rsync copies changed files. After that, the container is started (resumed) a second rsync copies changed files. After that, the container is
again. This results in minimal downtime, but needs additional space started (resumed) again. This results in minimal downtime, but needs
to hold the container copy. additional space to hold the container copy.
+ +
When the container is on a local filesystem and the target storage of the backup When the container is on a local filesystem and the target storage of
is an NFS server, you should set `--tmpdir` to reside on a local filesystem too, the backup is an NFS server, you should set `--tmpdir` to reside on a
as this will result in a many fold performance improvement. local filesystem too, as this will result in a many fold performance
Use of a local `tmpdir` is also required if you want to backup a local container improvement. Use of a local `tmpdir` is also required if you want to
using ACLs in suspend mode if the backup storage is an NFS server. backup a local container using ACLs in suspend mode if the backup
storage is an NFS server.
`snapshot` mode:: `snapshot` mode::