3PAR LUN does not shrink in size, when VMware virtual servers gets migrated to another LUN?

[Carl-Marius]

Hi,

I have VMware vCenter Server version 5.1.0 build 799731 and all my ESXi hosts runs ESXi version 5.1.0 build 799733.

As a SAN I am having 3PAR storage (3PAR InForm Management Console version 4.2.1.3).

I have created a LUN on 3 TB size as a Virtuel Thinly Provisioned LUN and 3PAR reports that Used User Space is 2.6 TB in size.

If I browse the LUN in VMware, I only have servers on the LUN with 1 TB in size and nothing more.

As a test, I have tried to vMotion move on server with a storage usage on 150 GB to another LUN and the other LUN grows correct in size, but the old LUN does not shrink in size.

Should 3PAR not shrink the disk in size, when VMware does not use the disk?

What number should I use as valid? the storage usage in 3PAR or in VMware?

Kind regards,

Carl-Marius

[Sheldon Smith · Accepted solution]

Do you have Zero Detect enabled on the Thin Provisioned Virtual Volume? 'Enabled' has not been the default setting in the past. You may need to enable Zero Detect on the TPVV, then use a vSphere function to zero out free space in the datastore. Create (and delete) a large "Eager Zeroed Thick” (EZT) virtual disk, or "vmkfstools -y <n>% <datastore>".

Check the HP 3PAR StoreServ Storage and VMware vSphere 5 best practices document at http://h20195.www2.hp.com/v2/GetPDF.aspx/4AA4-3286ENW.pdf

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[Carl-Marius]

Hi Sheldon Smith,

Thank you for your answer, this is the answer on my issue! :-)

Kind regards,

Carl-Marius

[JoachimT]

Sadly this does not work anymore with vsphere 5.5

Due to performance issues you have to use the CLI now to start the process if "UNMAP" in VMWare
See http://vmw.re/1BfDOG3

In ESXi 5.5, vmkfstools -y is deprecated and has been replaced by the esxcli storage vmfs unmap command. However, issuing UNMAP is still disabled by default. Space reclamation can be done manually by running the esxcli storage vmfs unmap command. For more information, see Using esxcli in vSphere 5.5 to reclaim VMFS deleted blocks on thin-provisioned LUNs (2057513)