rleon_vm
Enthusiast
Enthusiast

6.7U1 VSAN TRIM/UNMAP space reclaim on the vCenter Server Appliance itself

Hi all,

We have a 6.7U1 VSAN all flash environment.

The TRIM/UNMAP space reclamation feature is enabled on the VSAN cluster (The "vsan.unmap_support" Ruby command). Link to info.

We tested it on Windows guest OSes by running the following to force TRIM/UNMAP.

It works and Windows VMDKs instantly become smaller.

"Optimize-Volume -DriveLetter C -ReTrim -Verbose"

We would now like to test TRIM/UNMAP on the Thin Provisioned vCenter Server Appliance itself.

For example, to free up some Auto Deploy Image Builder left-behind deleted ISO disk space.

We tried running fstrim, but get the following:

"fstrim: /tmp: the discard operation is not supported"

Is there a way to force TRIM/UNMAP on the VCSA itself?

Thanks!

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3 Replies
TheBobkin
VMware Employee
VMware Employee

Hello rleon_vm,

Have you tried using blkdiscard instead of fstrim?

Are you logged into the vCenter as root?

VM Hardware version is 13 or higher?

UNMAP/TRIM Space Reclamation on vSAN | vSAN Space Efficiency Technologies | VMware

Bob

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rleon_vm
Enthusiast
Enthusiast

Hi Bob,

Turns out the official 6.7U1 VCSA ISO deployed it as HW version 10 instead of 14. (HW Compatibility with ESXi 5.5 and later).

I couldn't find anything about the pros and cons on upgrading the VCSA HA compatibility version, so I'll leave it as version 10 for now.

On the other hand, I tested and found that the VCSA does not have the "blkdiscard" command, only "fstrim" - which, as mentioned, does not work.

So, even if I upgraded it to HW version 14, neither commands would work anyway.

Is there an official word on doing TRIM/UNMAP on the VCSA itself? Seems like a no go at this point.

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TheBobkin
VMware Employee
VMware Employee

Hello rleon_vm

Try this:

# fstrim --all --verbose

You *should* get some output if it is discarding blocks.

Bob

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