CSV

TLDR: Newer versions of Windows will free blocks on a Cluster Shared Volume.

I work on a lot of Failover Clusters and about once a year it would come up that a customer had a situation with disk space. Usually it was older, out of support, versions of Windows and the scenario was that recently a bunch of VMs were moved from 1 Cluster Shared Volume (CSV) to another. The CSV volume on the FlashArray was not releasing the blocks. That left a customer with a handful of choices: