Here’s the official line on what a DDB DV does:
Deduplicated Data Verification cross-verifies the unique data blocks on disk with the information contained in the DDB and the CommServe database. Verifying deduplicated data ensures that all jobs that are written as unique data blocks to the storage media are valid for restore or Auxiliary Copy operations.
The first time you run it will always be a Full, but you can do Incrementals afterwards:
Run Incremental Verification
Use this option to verify the deduplicated data blocks that are newly added or data blocks that are not verified during the last data verification job.
The slowness is generally due to slow read speeds on the disks (much of the time, RAIDs are set to favor write speeds).
The options are detailed here:
https://documentation.commvault.com/2022e/expert/12398_data_verification_online_help.html
The Quick version differences are here. you can see why Quick is much shorter because it does not read the data blocks, it only ensures the ddb and blocks are met. However, the point of a DV here is to make sure the blocks are actually valid, so you should skip the Quick version. Just run the Full the one time (it will definitely take a while) and do Incrementals going forward.
This should be the schedule defaults already.
| Options | When to use | Applies To |
|---|
| Quick verification of existing jobs on disk and deduplication database | Use this option for a quick verification of all the deduplicated jobs (unique data blocks and all references to the blocks) on the disk with the DDB and on the CommServe database. This option validates if the existing backup jobs are valid for restores and can be copied during Auxiliary Copy operations. In comparison with the Verification of existing jobs on disk and deduplication database option, this option is faster because it does not read the data blocks on the disk. Instead, it ensures that both the DDB and disk are in sync. | Full and Incremental Data Verification Job |
| Verification of existing jobs on disk and deduplication database | Use this option if you want to verify all existing backups and to ensure that the new backups refer only to valid data blocks. This option validates if the existing backup jobs are valid for restores and can be copied during Auxiliary Copy operations. | Full and Incremental Data Verification Job |
