include::attributes.txt[]
endif::manvolnum[]
-'vzdump' is a utility to make consistent backups of running guest
-systems. It basically creates an archive of the guest private area,
-which also includes the guest configuration files. 'vzdump' currently
-supports LXC containers and QemuServer VMs. There are several ways to
-provide consistency (option `mode`), depending on the guest type.
+Backups are a requirements 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 of the backups and downtime of the guest
+system. Proxmox VE 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
+
+Before a backup can run, a backup storage must be defined.
+Refer to 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.
+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.
+
+.Scheduled Backup
+
+Backup jobs can be scheduled so that they are executed automatically on
+ specific days and times, for selectable nodes and guest systems.
+Configuration of scheduled backups is done at the Datacenter level in the GUI,
+which will generate a cron entry in /etc/cron.d/vzdump.
+
+Backup modes
+------------
+There are several ways to provide consistency (option `mode`),
+depending on the guest type.
-.Backup `mode` for VMs:
+.Backup modes for VMs:
`stop` mode::
-
-This first performns a clean shutdown of the VM to make sure it is
-stopped. It then starts the VM in suspended mode and uses the qemu
-backup feature to dump all data. If the VM was running, we start
-(resume) it immediately after starting the qemu backup task. This
-keeps the downtime as low as possible.
+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.
`suspend` mode::
-This mode does not really make sense for qemu. Please use snapshot
-mode instead.
+This mode is provided for compatibility reason, and suspends the VM before
+calling the `snapshot` mode. Since suspending the VM results in a longer
+downtime and does not necessarily improve the data consistency,
+the use of the `snapshot` mode is recommended instead.
`snapshot` mode::
-This mode simply starts a qemu live backup task. If the guest agent
-is enabled (`agent: 1`) and running, it calls 'guest-fsfreeze-freeze'
-and 'guest-fsfreeze-thaw' to improve consistency.
+This mode provides the lowest operation downtime, at the cost of a small
+inconstancy risk.
+It works by performing a Proxmox VE live backup, in which data blocks are copy
+while the VM is running. If the guest agent is enabled (`agent: 1`) and running,
+it calls 'guest-fsfreeze-freeze' and 'guest-fsfreeze-thaw' to improve
+consistency.
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].
-NOTE: Qemu backup provides snapshots on any storage type. It does
-not require that the underlying storage supports snapshots.
-
+NOTE: For VMs, this _snapshot_ mode relates to the fact that the backup is
+performed while the VM is running. This has here nothing to do with file systems
+snapshots and can be operated on any kind of storage.
-.Backup `mode` for Containers:
+.Backup modes for Containers:
`stop` mode::
'vzdump' skips the following files by default (disable with the option
`--stdexcludes 0`)
- /var/log/?*
/tmp/?*
/var/tmp/?*
/var/run/?*pid
projects / pve-docs.git / blobdiff