vzdump
Backup Utility for virtual machines and containers.
TLDR
Dump a guest virtual machine into the default dump directory (usually /var/lib/vz/dump/), excluding snapshots
$ vzdump [vm_id]
Back up the guest virtual machines with the IDs 101, 102, and 103
$ vzdump [101 102 103]
Dump a guest virtual machine using a specific mode
$ vzdump [vm_id] --mode [suspend|snapshot]
Back up all guest systems and send an notification email to the root and admin users
$ vzdump --all --mode [suspend] --mailto [root] --mailto [admin]
Use snapshot mode (no downtime required) and a non-default dump directory
$ vzdump [vm_id] --dumpdir [path/to/directory] --mode [snapshot]
Back up all guest virtual machines excluding the IDs 101 and 102
$ vzdump --mode [suspend] --exclude [101, 102]