I was involved in an interesting case recently. It was interesting because the customer was running an 8 node cluster, 4 disk groups per host and 5 x ~900GB hard disks per disk group which should have provided somewhere in the region of 150TB of storage capacity (with a little overhead for metadata). But after some maintenance tasks, the customer was seeing only 100TB approximately on the VSAN datastore. This was a little strange since the VSAN status in the vSphere web client was showing all 160 disks claimed by VSAN, yet the capacity of the VSAN datastore did not…