VMW0054: Disk letter is not shown when browsing data for backup that used disk filtering (VMware)

Issues with client IDs can occur after upgrading clients created in Commvault V9 or upgraded from V9 to Commvault V11.

Symptom

After performing a backup with disk filtering, a browse operation shows some disks with letter labels and other disks with volume labels.

The vsbkp.log file may display messages such as the following:

 
The disk is dynamic disk. Parse and add LDM Partitions for this disk.
...
Named the volume as $[Letter]:.
...
Volume $[Letter]: does not have all disks required
...
The disk is not dynamic disk. Parse and add DOS Partitions for this disk.
...
Named the volume as Volume$[n].
...
Dumping volume information for [Volume$[n]]

Cause

If a backup filters the disk that contains the operating system, the backup cannot load the registry hive and map volumes to drive letters on basic disks. Instead, volumes are named using sequential numbers.

For dynamic disks, the backup can get drive letters from the Logical Disk Manager (LDM) database without requiring the registry.

Resolution

If you need to preserve disk letters for basic disks, include the operating system disk in your backup.