Hello Naflan, Auto reclamation is supported but you need to match all requirements.  Here is a link to our best practice guide & if you look on page 69 it list out the requirements.  [URL] If you don’t match the requirements, then auto reclamation will not work.  Please let us know if you have any other questions.
Hi guys, we have a storage array Dell Compellent SCv2020 with vSphere 6.5 (build 7388607) in a customer premises. we recently had an issue that the storage entered to Emergency Mode.  from the DSM console, we can see 99% space is consumed from the array although we have migrated some VMs to different datastore (Storage vMotion).  after performed the vmfs unmap manually, 6TB spaces are reclaimed. we used thin provisioning in the data store. Over time, as we delete servers in VMware and VMotion from datastore to datastore that space will not be reclaimed on the array. I just want to know that, does it support auto-reclamation feature? (SCv2020)?. we have logged a support call with VMWare, they asked to check below settings on the array;  - ESXi does not support the automatic space reclamation on arrays with unmap granularity greater than 1 MB. If the unmap granularity of the backing storage is greater than 1 MB, the unmap requests from the ESXi host are not processed. - You need to verify the File Block Size on the Storage Array which should not be greater than 1 Mb. Anyone here can share ideas and feedback? Many thanks, guys.. also please help me on Compellent console command to find this.  Your response would be highly appreciated.  Naflan.    
Compellent SC2020 Auto-space reclamation does not work with vmware 6.5