Space Reclamation on Windows 2016

[Anthony_137]

Hi all,

I've noticed, something strange with few VVs on Windows 2016. Space used size on WIndows size is 502 GB where as space used size on 3PAR SSMC is 899 GB. 3PAR CLi show that :

                                 ---Adm--- ----------Snp---------- -----------Usr------------
                                 --(MB)--- ---(MB)--- -(% VSize)-- ----(MB)----- -(% VSize)-- ------(MB)------ -Capacity Efficiency-
 Id Name               Prov Type Rsvd Used  Rsvd Used Used Wrn Lim   Rsvd   Used Used Wrn Lim Tot_Rsvd   VSize   Compaction    Dedup
428 xxxx tpvv base 1024  594 15360    0  0.0   0   0 925696 920606 43.9   0   0   942080 2097152          2.3       --
------------------------------------------------------------------------------------------------------------------------------------
  1 total                        1024  594 15360    0              925696 920606                942080 2097152          2.3       --

So I've run optimized drive on Windows. Utility show 56% space efficiency.

Could you explain me why I've got this difference ? And how can I resolve it ?

[Anthony_137]

I research into eventlog and I've got this event id : 257 "was not optimized because an error was encountered: Neither Slab Consolidation nor Slab Analysis will run if slabs are less than 8 MB. (0x8900002D)"

[SUBHAJIT KHANBARMAN_1]

Try to check the below links,

https://www.rootusers.com/how-to-shrink-a-volume-in-windows-server-2016/

https://support.purestorage.com/Solutions/Microsoft_Platform_Guide/sss_Windows_Server_Features_and_Integrations/Windows_Space_Reclamation

Next thing to check how is the base type set in 3PAR and how it is set in Windows ? is it base 2 or base 10

Hope this helps!
Regards
Subhajit

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[Anthony_137]

Thanks for your links.
Therefore, I've see application eventlog error about defrag... I think this error blocks storage optimization on Windows.
Did you have seen this event ? (slab consolidation). I don't know If I can run defrag without -k option

[SUBHAJIT KHANBARMAN_1]

You need to understand what time you need to run defrag and what time you need to run Storage Optimization.. The error you are seeing as part of scheduled defrag (ScheduledDefrag) I guess which you can stop it by removing -k option as below,

Open Scheduled Tasks > Microsoft > Windows > Defrag

Open "ScheduledDefrag" > Actions

Highlight "Start a program" click the "Edit..." button.

Remove the "-k" entry from the "Add arguments" section

Click the OK button.  Events should no longer appear, if this is the only place Defrag is run from.

There's no need to run Storage Optimizer on thin provisioned LUNs that use an allocation size (also known as slab size) of less than 8 MB.

This is expected behavior because slab consolidation and slab analysis has been disabled on thin provisioned LUNs that have a slab size of less than 8 MB.

For more detailed information, please refer to the article bellw:

Storage Optimizer memory use increases when it runs on thin provisioned LUNs
http://support2.microsoft.com/kb/2964429

Hope this helps!
Regards
Subhajit

If you feel this was helpful please click the KUDOS! thumb below!

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[Anthony_137]

Thanks for your helps.
I've see your link.

I need to run storage optimization for my SSMC console. In fact, it report wrong size.

I'm on Windows 2016 failover cluster. I'm surprised that OS is concerned by this error.