About the exclude disk options for virtual disk selection
The backup policy Exclude disks tab has options to exclude virtual disks from a backup. By default, no disks are excluded. You should use this setting in most cases.
If you want to exclude disks from a backup, the other options are Exclude boot disk and Exclude all data disks. These options are intended for the virtual machines that have multiple virtual disks. You should use these options with care.
To exclude a boot disk or data disk, note the following requirements:
The virtual machine must have more than one disk.
NetBackup must be able to identify the boot disk.
The boot disk must not be part of a managed volume (Windows LDM or Linux LVM). The boot disk must be fully contained on a single disk.
The boot disk must include the following:
The boot partition.
The system directory (Windows system directory or Linux boot directory).
Important! The exclude disk options are meant only for the following cases:
Exclude boot disk: Consider this option if you have another means of recreating the boot disk, such as a virtual machine template for boot drives. If Exclude boot disk is enabled, the policy does not back up the boot disk.
Note:
When the virtual machine is restored from the backup, the virtual machine data for the boot disk may be missing or incomplete.
Note the following about Exclude boot disk:
If the virtual machine has a boot disk but has no other disks, the boot disk is backed up. It is not excluded.
If the virtual machine's boot disk is an independent disk, but the virtual machine has no other disks, the boot drive is backed up. The restored boot drive however contains no data, because NetBackup cannot back up the data in an independent disk.
If the virtual machine has a boot drive and an independent drive, the boot drive is not backed up. Only the independent drive is included in the backup. Since NetBackup cannot back up the data in an independent disk, the restored independent disk contains no data.
Refer to the explanation on independent disks in the following topic:
Adding a virtual disk and changing this option before the next backup can have unexpected results.
Exclude all data disks: Consider this option if you have a different policy or other backup program that backs up the data disks. If Exclude all data disks is enabled in a policy, that policy does not back up the data disks.
Note the following about excluding data disks:
If the virtual machine has only one disk (such as C:), that drive is backed up. It is not excluded.
If the virtual machine's boot disk is an independent disk, and the virtual machine has a separate data disk, the boot disk is backed up. The restored boot disk however contains no data, because NetBackup cannot back up the data in an independent disk.
Note:
When the virtual machine is restored from the backup, the virtual machine data for the data disk may be missing or incomplete.
Perform custom attribute based exclusion: If this option is enabled, NetBackup excludes the disks that have a custom attribute from the backup. The default value for this attribute is NB_DISK_EXCLUDE_DISK. You can use this default attribute or change the attribute name on the Exclude disks tab of the backup policy. Note that this option gives the VMware administrator control over which disks are excluded.
Note:
When a virtual machine is restored from the backup, the virtual machine data for the excluded disk may be missing or incomplete.
The attribute on the virtual machine must be populated with comma-separated values of controller IDs for the disks to be excluded.
If the custom attribute is not populated or does not exist on the virtual machine, none of the disks (except independent disks) are excluded.
If you remove disks from the custom attribute value between the differential backups, only those files that changed since the last backup are available to restore individually. You can restore the entire virtual disk or the VM, in which case all files are restored including those you cannot restore individually. After the next full backup, you can restore any of the files individually.
If you add disks to the custom attribute value between the differential backups, those disks are excluded from the next backup.
Specific disks to be excluded: If this option is enabled, NetBackup excludes the disks that you specify. Note that this option gives the NetBackup administrator control over which disks are excluded from backups.
Note:
When a virtual machine is restored from the backup, the virtual machine data for the excluded disk may be missing or incomplete.
On the Exclude disks tab of the backup policy, you must select the option Specific disks to be excluded and add each control ID.
If the disks do not exist on the specified controller and device IDs, none of the disks (except independent disks) are excluded.
If you remove controllers from the exclusion list between the differential backups, only those files that changed since the last backup are available to restore. All files are available to restore after the next full backup.
If you add controllers to the exclusion list between the differential backups, their disks are excluded from the next backup.
Caution:
The exclude disk options can have unintended consequences if these rules are not followed.