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SMSAP (Windows) Take a snapshot of a Clone

[ Edited ]

Hi,

We are using SM SAP 3.3 and SDW 6.4.2 on Win2008 Server (VM).

We've successfully created a clone of a database and mounted it on another server - this works very well.  However, we would like to be able to use SMSAP to take snapshots of the cloned database.  It appears that Snapdrive (and so SMSAP) doesn't support taking snapshots of LUN's backed be a clone. 

We have used the volume clone method, so the cloned LUN's are within their own volume (effectively) so I don't understand why there is a limitation in Snapdrive?  We can snapshot the cloned volume on the storage console, so I don't understand why snapdrive cannot do the same.  Does anyone have a view on this, or know if there's a workaround, or if this is a limitation that might disappear in a future release?  Looking at the docs for SDW 5.0, it appears to still be a limitation in that release also.

Thanks for any help,

Craig

Re: SMSAP (Windows) Take a snapshot of a Clone

Hi Craig,

This is in fact a limitation with SDW.  The volume you have cloned should have a volume name that begins with "sdw_cl_". In order to take a snapshot of the clone, you will have to "trick" SDW into thinking it is not a FlexClone volume. You do this by simply renaming the volume and removing the "sdw_cl_" prefix from the clone name.

After you do that, you should have no problem creating a snapshot.

Craig

Re: SMSAP (Windows) Take a snapshot of a Clone

Hi Craig,

Thanks for the info, I'll give that a try and report back.

I'd still like to know why the limitation exists at all.  I'm sure there's a good reason for it, but for the life of me I can't think what reason there can be to stop sdw from snapshotting a cloned vol.

C

Re: SMSAP (Windows) Take a snapshot of a Clone

Craig,

As I understand it, this is really a legacy "bug" in SDW. Originally the cloning feature was used for database verification, especially in SQL environments. It was not really intended to be used for provisioning new environments. The clone was supposed to be attached to a verification server and then discarded.

However, as users, we always find ways to use these clones for something else. I think the SDW team has been working on features and functionality rather than closing gaps like this.

We have asked that this "feature" be extended to support things exactly like you are doing. I would imagine it would appear in a future release.

Craig