Yes, there are quite a lot of blog posts about UNMAP out there. But do you really get it? Me not. What I do now so far is, that It does reclaim space on your VMFS Volumes. So far so good. But here my question.
Why the hell VMware does not provide us the possibility to do this automatic? Yes, I know I can script that one and run it as a scheduled task but this is not solving all my problems. For example, VMware Horizon View. During recomposes, I need to be worried about my Array to get full because quite a lot of VMs are getting deleted and new ones created. Running unmap afterwards could already be too late.
Yes, I know in the past Storage Arrays not always handled unmaps nicely, what maybe was a good reason to go for a non-automatic way to handle this.
But in these days where all Storage vendors go for the Flash Arrays and real-time deduplication leads to a new dimension of overprovisioning/thinprovisioning volumes it’s an absolutely necessary feature, and the fact that it already was implemented in previous version tells me, that it’s absolutely realizable. So why not doing it?
Another “side-question” about unmap:
If I delete a 1 TB VM on a Datastore and afterwards create another VM of 1TB is this VM created on the Blocks of the Old VM? Or will the storage array now say me my I am currently using 2 TB?
Thanks in advance
