Can't reduce HDD size (thin provisioning)

[Kazanovas]

Hello,

Running ESXi 6.5.0 version 650.9.6.0.28.

We have several VMs (Windows and Linux).

When trying to reduce the size of a hard disk, we get the message:

Enter a disk size which is larger than its original capacity.

Disks are thin provisioned.

Are we missing something or this is not possible with ESXi 6.5?

Thanks

Alex

[vijayrana968]

What's the point to reduce size of thin disks as they are taking space of actual occupied data. Thin disk wont be taking up extra space than the actual anyway. Or this is totally different task your'e executing !

[a_p_]

IIRC reducing a virtual disk's provisioned size has never been supported.

Reducing the disk size without modifying the guest operating system's partitions would likely cause data corruption and/or loss.

André

[compwizpro]

What is the goal to reducing the VMDK size?  Did you delete files in the guest and am trying to reclaim that space from the VMDK?  If so, reference this thread here: Sdelete a thin provisioned Disk

If you want to just resize the VMDK to a smaller size, I believe you could use vCenter converter and convert the specific VMDK.  Otherwise you could create a new VMDK and use robocopy if windows or something like rsync if linux to manually copy the contents to the new volume.

[Dave_the_Wave]

I think it's by design.

The VM can't be smaller than the logical drive inside the VM, or else that VM could never start.

Can you try this? To make your VM disk smaller, use a partitioning app to reduce it logically first, then perhaps the VM can be reduced down to the level that was done in the GOS.

Think how it allows the opposite. When you edit for a larger VM disk, you still need to go into the GOS to expand the logical drive, as the case with Windows Server.

[hussainbte]

As mentioned, if the disk is thin provisioned, there is no point shrinking it.

for think provisioned disks, where the Guest OS is not utilizing the allocated space, one way to shrink is to do V2V.

Check below link

Shrink a VMware Virtual Machine Disk (VMDK) – virtualman

[vijayrana968]

Additionally, you need to defrag the disk before shrinking if thin provisioned vmdk has grown due to data which you might have deleted later.