topic Re: Overprovisioned in StoreVirtual Storage

Overprovisioned

ArjanA — Wed, 14 Mar 2012 14:49:39 GMT

Hi,

One of the P4000 clusters that I administer stays 'Overprovisioned'.

The cluster total space used is 81%.

All volumes are full provisioned. There are several snapshots that are Thin provisioned.

Do I have to take action?

How should I take deal with this?

Re: Overprovisioned

ArjanA — Wed, 02 May 2012 12:42:15 GMT

All volumes are thick provisioned, but there are several snapshots that I think are causing the overcommitment:

VSS-FILE01-0 Created by HP P4000 VSS Provider Normal (Temp space: Normal) Network RAID-10 (2-Way Mirror) Thin 25-1-12 2:01:32 uur CET

VSS-MAIL01-0 Created by HP P4000 VSS Provider Normal (Temp space: Normal) Network RAID-10 (2-Way Mirror) Thin 13-1-12 3:15:40 uur CET

VSS-MAIL01-1 Created by HP P4000 VSS Provider Normal (Temp space: Normal) Network RAID-10 (2-Way Mirror) Thin 28-12-11 2:53:36 uur CET

VSS-MAIL01-2 Created by HP P4000 VSS Provider Normal (Temp space: Normal) Network RAID-10 (2-Way Mirror) Thin 28-12-11 2:53:36 uur CET

VSS-MAIL01-3 Created by HP P4000 VSS Provider Normal (Temp space: Normal) Network RAID-10 (2-Way Mirror) Thin 13-1-12 3:15:40 uur CET

How can I get rid of these snapshots? Kind regards, Arjan Anthonisse

Re: Overprovisioned

Jitun — Wed, 02 May 2012 15:56:03 GMT

Taking Snapshots with Thick/Full Provisioned Volumes on P4000 is not space efficient.

The Volume which is Full Provisioned will always Allocate the Size that it was created with (multiplied by the number of copies it has -- Network RAID)

The Thin Provisioned Snaphots will consume additional space (the amount of data the volume contains multiplied by the number of copies it has -- Network RAID)

So if you plan to use Snapshots, I would prefer changing the Volumes to Thin Provisioned.

That way, the space consumed including the Snapshots will be equal to the amount of data in the volume multiplied by the number of copies it has -- Network RAID.

So for Example a 10Gb Network RAID 10 Volume which contains 3Gb of data.

Full Provisioned volume with snapshots will consume

[10Gb(Volume Reserved) + 3Gb(Snapshot) ] x 2 (Network RAID 10) = 26Gb

With Thin Provisioned Volume (assuming you have just taken a snapshot)

[0.5Gb (Volume Size) + 3Gb (Snapshot)] x 2 (Network RAID 10) = 7Gb

As you can see there is a huge difference in amount of Space consumed in the Cluster.

Good thing with P4000 is that you can change the Provisioning on the Fly.

Just Edit the Volume to Thin Provision and it will be done. Host will never know the change.

Re: Overprovisioned

ArjanA — Wed, 09 May 2012 09:55:14 GMT

Thanks for the explanation about snapshots and thin/thick provisioning.

The snapshots are created by software, I don't know which software.

I assume BackupExec, but I am not sure.

How can Icheck which software creates the snapshots?

How can I get rid of the existing snapshots?