A subclient identifies a group of instances to be backed up, and associates the subclient content with a storage policy that identifies where backup data will be stored.
You can add instances to subclient content manually or define automatic discovery rules to identify instances for a subclient.
A default subclient is created automatically for each backup set. When first created, the default subclient includes the entry '\' on the Content properties to represent "All unprotected instances," ensuring that all instances from the configured Google Cloud Platform service account will be backed up if they are not covered by another subclient.
You can create additional subclients to back up selected instances based on discovery rules. This approach can be used to provide different policies, options, or backup schedules for different categories of instances, based on the instance name, host, guest operating system, storage location, or tag. You can also create filter rules to exclude instances from backup set or subclient content.
When an instance is included in a user-defined subclient, it is automatically excluded from the default subclient. This prevents the duplicate backup of any instance by the default subclient. (Duplicate backups still occur if an instance is included in multiple user-defined subclients.)
Note
If a subclient is deleted, backed up instance data can still be restored from the backup set that contained the deleted subclient.