HPE Storage Users Group

Hi,

We have had a new cage installed into our 3Par SAN, which has given space for 3 new LUNs of 2.5Tb in size.
The issue we face is that the tune of the system should have been performed before the new LUNs were created. When I try to tune virtual volumes I'm presented with an error that there is insufficient space.

The new LUNs are not being used by any hosts as yet. The LUNs have been added to a virtual volume set, but a datastore rescan has not been performed at the Vmware level.
My question is - is it safe to remove the LUNs from the volume set and then remove the virtual volume(s) to create free space for the tune to be performed?
If it is safe to remove the LUN, would the 2.5Tb space be available and seen immediately or are there pre/post tasks that would need to be completed to make it available again?

Kind regards,
Ben

What type of volumes are you using? Only fully provisioned volumes will allocate the space before you start using it. When you delete a fully provisioned volume, you need to run "Compact CPG" to release the space back to the system. With fully provisioned volumes, that should be rather quick.

If you are using anything other than fully provisioned it seems that something may be wrong with your add-on (incorrect cabling or missing licenses).

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The views and opinions expressed are my own and do not necessarily reflect those of my current or previous employers.

Thanks for the quick reply.
We are using fully provisioned volumes so will need to run compact cpg.
Is that something that increases system load and should be done out of hours?

Around the subject of tuning the volumes once I have the space back - is it recommended to manually tune each volume or to run tunesys and let the system perform the tuning?

I would run tunesys, just because its less manual work and doesn't require DO license.

I would compact cpg with the -notune option when using fully provisioned. That should clean up most as the fpvv should be stored sequential.

_________________
The views and opinions expressed are my own and do not necessarily reflect those of my current or previous employers.

Thanks again for the advice.

Hi Mammagut,

When we delete the LUN permanently from Storage it will release the free space instantly right ?

Do we need to run the compact CPG manually ?

Regards,
KK

It is released to the cpg, so you need to do compact to use the space in other cpgs.

_________________
The views and opinions expressed are my own and do not necessarily reflect those of my current or previous employers.

Oh k.. Thank you so much Mammagut.

I got this doubt because we were running unmap command from VMware end to release the free space and then reclaiming it from storage end using compactcpg command.

Later support guys suggested us to directly delete the LUNs to reclaim the free space instantly.

Regards,
KK

Thanks for the advice last week MammaGutt. The procedure to remove the LUNs went well.

Just thought I would pass on what happened.

First I removed the volumes from the virtual volume set, and then removed the virtual volumes.
Initially 3/4 of the free space came back immediately. I waited to see if the remaining portion would come back, after an an hour I was still waiting. Until I closed and reopened the 3Par management console I didn't see all of the free space.
Even after the free space was reported in the console correctly I was still unable to tune the LUNs due to insufficient free space?!
Having tried to start the tune a couple of times I noticed that the amount of free space that was available being reported in the error was increasing slightly, approx 80Gb every 30 mins.

After a number of hours I was able to start tuning the LUNs.