Commvault backs up all of the virtual machines (VM) identified on the Content tab for a subclient.
The backup process creates simple hot clones of VMs. The VMs are cloned in a serial fashion, the cloned disks are attached to the VSA access node, and the data is read and transferred in parallel based on the number of data readers. Backups are crash consistent.
You can perform full, incremental, or synthetic full backups of virtual machines. The first backup of a virtual machine is always a full backup, regardless of the selected backup type.
Backups of virtual machines are performed in round-robin sequence.
Considerations
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When a virtual machine is discovered during backup, a client for the VM is created in the CommCell Console if one does not already exist. If a virtual machine with spaces or special characters in its name is discovered during backup, the spaces or special characters are replaced with underscores ('_') when creating the VM client name that is displayed in the CommCell Console. The VM name with spaces or special characters is still displayed on the Virtual Machine Status tab for the backup job, in the backup job summary, and in reports that include the VM name. The following special characters are replaced:
[ \ \ | ` ~ ! @ # $ % ^ & * + = < > ? , { } ( ) : ; ' \ " \ \ s / ]
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A hot clone duplicates the configuration and data for a virtual machine that is running. Hot clones are only available for machines using OCFS2-based file systems, using either iSCSI or fibre channel storage for the source and destination repositories.
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Oracle VM does not support hot clones of virtual machines residing on an NFS repository. In that case, you must shut down the virtual machine to perform a backup.
Backup Types
You can perform the following types of backups, either immediately or on a schedule.
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Full backups: Back up the entire virtual machine. This is the most comprehensive backup.
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Incremental backups: Back up virtual machine data that has changed since the most recent backup.
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Synthetic Full backups: Consolidate virtual machine data from the most recent full backup with subsequent incremental backups.
For more information on backup types, see Backup Options.
Note
By default, the option to perform a differential backup is not included in the Backup Options for Subclient dialog box.
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To display the Differential backup option, add the bEnableVSADifferentialBackup additional setting to the CommServe system as shown in the following table.
For instructions on adding additional settings from the CommCell Console, see Adding or Modifying an Additional Setting.
Property
Value
Name
Category
CommServDB.Console
Type
Boolean
Value
true
What Gets Backed Up
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Virtual machines (Windows and Linux, powered on or powered off)
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Virtual disks attached to a guest VM
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VM configuration file
What Does Not Get Backed Up
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Physical disks attached to a guest VM (skipped during backups)
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Oracle VM templates