A server backup is a disk image created in the Image store from a running server instance. The backup command manages the number of archival copies to retain.
Compute v2
Create a server backup image
os server backup create
    [--name <image-name>]
    [--type <backup-type>]
    [--rotate <count>]
    [--wait]
    <server>
Name of the backup image (default: server name)
Used to populate the backup_type property of the backup image (default: empty)
Number of backup images to keep (default: 1)
Wait for operation to complete
Server to back up (name or ID)