About Hyper-V online and offline backups for VSS
A Hyper-V virtual machine can be in any of the following states: Running, Saved, Paused, or Off.
In addition, Microsoft provides the following two types of Hyper-V virtual machine backups for the VSS backup method:
Online | Specifies that a virtual machine that is in the Running state is briefly quiesced for the backup. User access during the backup continues without interruption. |
Offline | Specifies that a virtual machine that is in the Running or Paused state is rendered temporarily inactive. It is returned to its original state before the backup completes. User access during the backup is interrupted. |
Note:
Type of backup (online or offline) is a Microsoft designation and is not configured in NetBackup.
The following table shows the possible combinations of virtual machine state and the type of backup (online or offline) when you use the VSS backup method.
Table: VSS backup: State of virtual machine before and after restore
State at the time of backup | Type of backup | State after restore |
|---|---|---|
Running | Online | Off |
Running | Offline | Saved |
Saved | Offline | Saved |
Paused | Offline | Saved |
Off | Offline | Off |
Note: The WMI backup method (for Hyper-V Server 2016 and later) does not employ online vs offline backups.
See WMI backup method: State of the virtual machine before and after restore.