I have a very odd issue myself or my co-workers have never seen before. I've been working w/ VMware support on this for a couple months now, to no avail. I'm curious if anyone in the community has ever run across this, because it's quite hard to get to the root of.
Issue: We have several storage DRS clusters in which the datastores will flap back & forth regarding their available free space. The swings are quite large...in the terabytes. This causes us VM deployment failures, and disk management (think disk expansion) task failures. When we SSH into the hosts and look at the amount of free space a host sees for a datastore that is flapping, it shows what we (myself and VMware support) believe is the correct value, where vCenter sees a different value. This behavior is observed on many hosts, it's not an isolated instance. From everything I can tell, it's vCenter that is reporting the wrong values for free space in a good number (but not all) datastores.
vCenter: 6.5 U2
hosts: 6.5 U2
Storage Array: multiple vendors, not one particular vendor array
sDRS settings: We've tweaked these settings every which way we can think of to try to determine the root cause, all to no avail. We've even disabled sDRS, it did not make a difference.
Anyone ever see an issue like this? We're quite stumped, but need to get to some sort of resolution.
Thanks in advance,
Jay