Minimize the vSAN storage space that VM occupied?

[klancy43]

Hi folks,

I got a vSphere version 6.7 environment of AF vSAN cluster and am wondering about if there's a mechanism to make the VMs (that utilize vSAN storage)use the least amount of space so that to free up more space for vSAN storage.

The current policy applied to the VMs are "thin provisioning" + "FTT=1(raid5)" and I guess this combination is the best one to consume the least storage space(if I require protection for VM objects.)?

Sorry for the stupid question if it is.

Is there a method to reclaim space from the VM's vmdk (to release to vSAN)? I thought the OS in VM only utilize some amount of space but from the vCenter we can see the vmdk is quite larger than what the OS consume...

[depping · Accepted solution]

Unmap/Trim is what you are looking for: https://core.vmware.com/resource/vsan-space-efficiency-technologies#sec2-sub1

But I would recommend you go up to the highest update level first before you use it.

[klancy43]

Hi @depping 

thanks for answering!

I just noticed this doc and it seems that this is what you are talking about but I'm not 100% sure about it.

Are these the same ?

[depping]

Yes that is the same, UNMAP!

[klancy43]

@depping 

So in order to achieve the space reclamation from guest-OS and release to vSAN storage instantly, 

I must to perform the "vsan.unmap_support –enable" command on vSAN (cluster-level) and the inline unmap such as "mount -o discard" for linux (OS-level)???

[depping]

yes, just follow the documentation.