Is it recommended having a single volume with multiple LUNs in it ?

[lcbtitsupport]

Hi

I would greatly appreciate it if somebody could assist:

Current Scenario

We have a FAS2020 with 10 Volumes. Each volume has a LUN within it. Each LUN is the  virtual hard disk of a virtual server. We use Citrix Xen server as the hypervisor .

I thought I could save storage by putting all 10 LUNs in single volume and then deduplicate that volume.

Questions

1) Is it recommended having a single volume with multiple LUNs in it?

2) If the answer to question 1 is yes, and that volume is being snapshotted, would I be able to restore a single LUN from a snapshot? (rather than all of them?)

Thank you

Christos

[adamfox · Accepted solution]

If you are anticipating getting much space back (think OS images), then yes you can put multiple LUNs in the same volume and de-dup it.  We are doing this at several customers.

You can always get a LUN back from a snapshot either through a manual copy (slower), or a single filer SnapRestore (quicker in most cases.  For the later you would need a SnapRestore license.

[lcbtitsupport]

Thank you Adam.

Below are the answers I got from a NetApp Technical Support Engineer for the same questions:

1) It is not recommended having a volume with 10 LUNs reason being is if one LUN went off line it would take the whole volume off line. So having 10 LUNs in 10 different volumes is the best practice.

2) If you had 10 LUNs in a volume, you could not restore an individual LUN from the snapshot because it sees at block level and not file level.

I am a bit confused now..Do you know if NetApp has realased a whitepaper or some formal guidelines or best parcise guide about this?

[pascalduk]

lcbt-itsupport wrote:
Thank you Adam.
Below are the answers I got from a NetApp Technical Support Engineer for the same questions:
1) It is not recommended having a volume with 10 LUNs reason being is if one LUN went off line it would take the whole volume off line. So having 10 LUNs in 10 different volumes is the best practice.
2) If you had 10 LUNs in a volume, you could not restore an individual LUN from the snapshot because it sees at block level and not file level.
I am a bit confused now..Do you know if NetApp has realased a whitepaper or some formal guidelines or best parcise guide about this?

1) Works only if do not have a large amount of LUNs. Otherwise you can run into number of volumes limits. And 1 LUN taking down the rest will only happen when your volume runs out of space.

2) Yes you can. Either use snap restore for a file (the LUN in this case) or LUN clone/split.

[mrcenterprises]

So how are you guys taking your snapshots? are you using a NetApp application to do this? ie SnapDrive or SnapCreator, or are you having to use a SnapManager?