Backup Exec 21 - Deduplication Storage not releasing as much space as it should even after expiring the backup sets

Problem

Backup Exec Deduplication Storage not releasing as much space as it should even after expiring the backup sets

Error Message

No errors seen. The Dedupe folder reclaims space but comparatively less.

Cause

Data full check does not complete the rounds.

Solution
 

This Issue is fixed in Backup Exec 22 release.

Follow the below procedure for Backup Exec 21 

The reclaim process is described in Technical article 100008765

Backup sets in Deduplication Storage folder gets deleted after the sets expiration time has come.  This deletion of the set from BE, triggers the segments and references to be removed from Deduplication Storage folder.
Even after the dereferencing takes place, the space allocated in Deduplication storage is not given away to the operating system and a process called compaction is run automatically in the background to reclaim the space.

The above is the normal chain of events that help to release space from deduplication storage and should do the job is every case.

In some instances the space is still not reclaimed and additional commands have to be triggered.
Take a note of the Space allocated for containers value by running the command crstats.exe --verbose --convert-size
Note: Commands need to be run from Command Prompt -> Run as administrator and change directory to BE Install Path.

(i)  pddecfg -a enabledataintegritycheck
(ii) pddecfg -a startdatafullcheck

To check the difference in Space allocated for containers it is better to stop the backups to Deduplication Storage for 24 hours after the above two commands are run.

If the above helps to bring down the space allocated for containers value, then run the above commands one after the other every 15 days or a month to keep the storage size in check.

BE 21 Only -> The Catalog Logical size value and Deduplication ratio reported when crstats command is run are not correct and should not be used to discuss space ideally needed by the deduplication storage to accommodate the front end data.