Virtual machine backup glossary
Short definitions for the words these guides use. Each term also appears in the visible list below.
Use the definitions as a map, then read the guide that applies to your hypervisor. The same word can mean a checkpoint in one product and a backup job in another.
If a vendor screen uses a different label, match it to the failure domain: does the copy survive the loss of the original disks?
- Snapshot
- A differencing point stored with the original virtual disks. It is not an independent backup.
- Backup
- A separate copy of a virtual machine that can be registered or imported without the original datastore.
- RPO
- Recovery point objective: how much recent work you can afford to lose.
- RTO
- Recovery time objective: how long you can wait before the guest must serve traffic again.
- Quiesce
- A pause that lets applications flush writes before a snapshot or backup.
- Crash-consistent
- A copy of disks as they were, without an application flush. The guest may need file-system repair.
- Application-consistent
- A copy taken after the guest flushed databases and logs.
- Off-site copy
- A backup kept in another failure domain, such as another site or a separate account.