Backup Rules for VMs

Applicable to Classic mode only

File-system consistent backups require you to freeze I/O operations before backing up the volumes and unfreeze them after the backup is created. Portworx Backup internally creates and runs pre-exec/post-exec rules (freeze/thaw rules) for all VMs before and after creating the VM backup.

If you want to take file-system consistent backups, the following sample values for the pod selector and action fields let you create pre-exec and post-exec rules. Freeze/thaw rules execute virt-freezer within the virt-launcher Pod.

Refer to Add backup rules to create pre-exec and post-exec rules for the VMs.

note

• For Portworx Backup to execute the freeze/unfreeze (thaw) rule, both the VM and qemu-guest-agent must be in a running state.

• Portworx Backup comes with built-in pre-exec and post-exec rules that freeze and unfreeze the VMs respectively. If you disable the custom rules option while creating VM backups in the Portworx Backup web console, the built-in pre-exec and post-exec rules are applied to your backups. For more details on how to disable the built-in rules, see this topic.

note

The Pod Selector field value can be found in the virt-launcher Pod.

The following illustration provides sample freeze and unfreeze rules for a VM:

The following shows sample values for the Pod Selector and Action fields for pre-exec and post-exec rules:

• Pre-exec rule value for freeze:

  • Pod Selector: vm.kubevirt.io/name=<vm-name>
  • Container: compute
  • Action: /usr/bin/virt-freezer --freeze --name <vm-name> --namespace <vm-namespace>

  Replace <vm-name> and <vm-namespace> with the actual name of the VM and VM namespace respectively.

• Post-exec rule value for unfreeze/thaw:

  • Pod Selector: vm.kubevirt.io/name=<vm-name>
  • Container: compute
  • Action: /usr/bin/virt-freezer --unfreeze --name <vm-name> --namespace <vm-namespace>

  Replace <vm-name> and <vm-namespace> with the actual name of the VM and VM namespace respectively.

The action for freeze/unfreeze can be found by describing the virt-launcher Pod of the VM.

note

For every VM that you want to back up, ensure that a pod selector, action, and container specific to the VM exist in the pre-exec and post-exec rules.