A subclient identifies a group of virtual machines to be backed up. Each subclient is associated with a storage policy that identifies where backup data will be stored.
Selecting Virtual Machines for Backup
You can browse for and manually add virtual machines or other Hyper-V objects to the subclient content for backup. You can select objects, such as hosts, virtual machines, volumes, and cluster shared volumes (CSV). When you select a Hyper-V object, all its child objects are automatically selected for backup. For example, if you select a host, all the virtual machines on the host are automatically selected for backup.
The Browse window provides the following views for a Hyper-V cluster:
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Hosts View (Default)
Use this view to select specific hosts and clusters for backup.
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VMs View
Use this view to select specific virtual machines. VM view is useful for selecting a specific virtual machine on a host or for selecting multiple virtual machines across different hosts.
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Storage View
Use this view to select all the virtual machines from a CSV or a local volume.
For instructions on selecting virtual machines for backup, see Adding a User-Defined Subclient.
Automatic Discovery of Virtual Machines for Backup
In addition to manually selecting virtual machines for backup, you can also define discovery rules to automatically assign virtual machines to the subclient content. You can combine multiple rules by using Operators to define a Rule Group. For instructions on defining rules for subclient content, see Adding Subclient Content Using Discovery Rules.
Excluding Unprotected Virtual Machines in the Default Subclient
By default, all the virtual machines from a Hyper-V cluster are automatically included in the default subclient of any backup set. This behavior is designed to ensure that all virtual machines are backed up. However, the following virtual machines are excluded from the default subclient:
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Virtual machines that are included in a user-defined subclient. Inclusion in the user-defined subclient prevents the duplicate backup of any virtual machine.
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Virtual machines on the Hyper-V server where the Virtual Server Agent is not installed.
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Virtual machines excluded by filters defined for the default subclient.
For instructions on manually excluding unprotected virtual machines in default subclient, see Excluding Unprotected Virtual Machines in Default Subclient Content.
Filtering Virtual Machines from a Backup
You can exclude specific virtual machines from a backup by defining filters. For instructions on filtering virtual machines in the subclient content, see Defining Filters for Subclient Content.
Crash-Consistent Backups
By default, backups are application-consistent and include pending transactions. If a backup of a virtual machine needs to capture only stored data, a crash-consistent backup can be performed very quickly while the virtual machine remains online. For more information on enabling crash-consistent backups for a subclient, see Enabling Crash Consistent Backups.Configuring Backups for Virtualized Domain Controllers
Domain Controllers running on virtual machines have more restrictions than the ones running on physical machines.
Backup operations performed on virtual machines using the Virtual Server Agent may result in some problems when the virtual machine is restored. This is because the Active Directory data, log files, registry settings, system volume folder and other various operating system elements that are mandatory for Domain Controllers are not backed up in the process, thereby resulting in several issues after the restore.
To avoid these issues, install the Windows File System Agent on the virtual machine and back up the system state of the virtual machine with domain controllers.
System State includes all the mandatory elements for physical and virtual machine domain controllers. The Virtual Server Agent can be used to protect additional data on the virtual machine.
For information on configuring system state backups, see Configuring System State Backups.
You must backup a minimum of one domain controller in the forest every tombstone number of days. For more information, refer to Running Domain Controllers in Virtual Hosting Environments.