backup exec\data contains a lot of folder file-extents-b files

I have a Backup Exec 15 (14.2 Rev1180.3157) and noted that C:\ drive on the Backup Server starts to run out of space.

After a quick investigation it looks like Backup Exec\Data folder has size of 162 GB. It seem to be overwhelmed with files named "file-extents-b-<vm name>-<date>.b files. Some of these files have size more than 80 MB which is multiplied by number of such files give huge numbers.

This issue seem to consume space very fast.

Did anyone face similar issue?