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 Post subject: New 3Par User - Thin Provisioning and VMWare Question please
PostPosted: Wed Nov 08, 2017 9:43 am 

Joined: Wed Nov 08, 2017 8:57 am
Posts: 3
I just have a question regarding thin provisioning on the 3Par side and thick provisioning on the VMWare side..

Say I have provisioned a 1TB virtual volume to a host set on the 3Par..

In VMWare, I create a 900GB Thick Provisioned VMDK for a Windows VM.. When I go into the datastore browser in VMWare it shows a 900GB file..

Inside Windows of the VM, it's currently only using 100GB of space.. In VMWare, it's still using 900GB on the datastore as it was thick provisioned..

On the 3Par side, would it only be using 100GB of this virtual volume?

Thanks!!


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 Post subject: Re: New 3Par User - Thin Provisioning and VMWare Question pl
PostPosted: Wed Nov 08, 2017 11:42 am 

Joined: Wed Nov 09, 2011 12:01 pm
Posts: 184
Basically yes.

However if you write another 100GB file in the Windows VM and then delete it you will see;

Windows 100GB
VMware 900GB
3PAR 200GB

If you wanted that 100GB back in 3PAR then you'd need to run something to write zeros over the deleted file blocks in Windows.


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 Post subject: Re: New 3Par User - Thin Provisioning and VMWare Question pl
PostPosted: Wed Nov 08, 2017 11:49 am 

Joined: Wed Nov 08, 2017 8:57 am
Posts: 3
Thanks for the reply!

So if it was Windows 2012 or above, by default it does the weekly "drive optimize" which is like unmap / writing zeroes so the 3Par's ASIC will then reclaim the space on the 3Par side?


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 Post subject: Re: New 3Par User - Thin Provisioning and VMWare Question pl
PostPosted: Wed Nov 08, 2017 2:40 pm 

Joined: Mon Sep 21, 2015 2:11 pm
Posts: 454
walter_white wrote:
Thanks for the reply!

So if it was Windows 2012 or above, by default it does the weekly "drive optimize" which is like unmap / writing zeroes so the 3Par's ASIC will then reclaim the space on the 3Par side?


With RDM, yes. With VMDK files on VMFS5, no.

With ESXi 6.5 and VMFS6 you could use thin in vmware and thin in 3PAR and the unmap commands will pass thru and reclaim it on the 3PAR as well.


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 Post subject: Re: New 3Par User - Thin Provisioning and VMWare Question pl
PostPosted: Wed Nov 08, 2017 2:47 pm 

Joined: Wed Nov 08, 2017 8:57 am
Posts: 3
MammaGutt wrote:
walter_white wrote:
Thanks for the reply!

So if it was Windows 2012 or above, by default it does the weekly "drive optimize" which is like unmap / writing zeroes so the 3Par's ASIC will then reclaim the space on the 3Par side?


With RDM, yes. With VMDK files on VMFS5, no.

With ESXi 6.5 and VMFS6 you could use thin in vmware and thin in 3PAR and the unmap commands will pass thru and reclaim it on the 3PAR as well.


Thanks for clarifying that! Actually doing some 3Par training this week and he didn't mention it was specific to RDM.. I was pretty excited at the thought it was in VMWare too.. Oh well.


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 Post subject: Re: New 3Par User - Thin Provisioning and VMWare Question pl
PostPosted: Thu Nov 09, 2017 3:45 am 

Joined: Wed Nov 01, 2017 9:14 pm
Posts: 1
Hi all,

If i checked enable zero detection, is my deleted space auto reclaim or i must have sdelete to reclaim that deleted space.
My storage is 3par 7400

Thank


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 Post subject: Re: New 3Par User - Thin Provisioning and VMWare Question pl
PostPosted: Thu Nov 09, 2017 4:37 am 

Joined: Mon Sep 21, 2015 2:11 pm
Posts: 454
pepsichanhvn wrote:
Hi all,

If i checked enable zero detection, is my deleted space auto reclaim or i must have sdelete to reclaim that deleted space.
My storage is 3par 7400

Thank


It depends on how it is deleted. For Windows it needs to be cleared from the recycle bin.
If deleted on bare-metal Windows 2012 or later then unmap is sent and space is reclaimed.
If deleted on bare-metal Windows 2008 or earlier, then sdelete is required.
If deleted in Vmware on VMFS then esxcli unmap is required on VMFS5, for VMFS6 is sends unmap and space is reclaimed.
If deleted in a virtual machine using a VMDK it is reclaimed if the OS is writing zeros when deleting, however most OSes and filesystems only delete pointers and possibly send unmap command. For VMFS5 those unmap commands gets filtered out by Vmware. With VMFS6 and thin VMDK and thin VV on 3PAR the unmap commands is passed thru to the 3PAR and space is reclaimed.


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