2010-07-26 07:48 AM
We have our exchange data on LUNs served from our 3170 cluster.
these LUNs were provisioned using NetApp System manager.
We now want to begin using SnapManager for exchange and need to install SnapDrive.
I'm being told that in order to use snap drive/snapmanager we need to install SnapDrive and have it provision the LUNs we want to manage. That LUNs created without SnapManager cannot be managed by snapdrive and so we can't use snapmanager. There is, apparently, a difference between NetApp LUNS and NetApp SnapDrive LUNs.
What would be the procedure to get this working? Do i have to install snapdrive, provision new luns, move the exchange data to the new, SnapDrive provisioned LUNs, remove the old LUNs and reclaim that space?
Seems like a lot of work that I'd prefer to avoid.
2010-07-26 12:23 PM
On a Windows 2003 machine you would need to use SDW to create LUNs so the data blocks from the NTFS file systeme are aligned with the WAFL for better performace. However, you can use snapdrive to connect a previously created LUN on the NeApp. So, if you would like to correctly align the file systems, you would need to follow the procedure you just discribed. The LUN's movement is made when you first run the snapmanager for exchange wizard, it gives you an option to move the databases for you to a lun that you specify, so it si quite simple.
On windows 2008 I think that this restriction of misalligned datablocks is automatically fixed by itself.
Also another thing you should consider, as a best practice to protect your Exchange system, is to save your snapinfo logs on a separate LUN than the one used to store the Exchange Logs. This is recomended since this folder rapidly increases and it is proportional to the snapshot retention period.
2010-07-26 12:25 PM
We often put snapinfo in the log lun so that ntfs hard links are used instead of a copy for faster backups. This doesn't work for SMSQL but is support by SME and leverages ntfs hard links.
2010-07-26 12:28 PM
If a windows lun already on the fas, then it is already aligned (if not a vm, but a native windows lun). SnapDrive should be able to mount the existing lun... there were some cases in the past where it didn't work but worth opening a case and getting ps involved to assist if needed...but should be good to mount the existing netapp luns with snapdrive...you could test this with a lun clone or flexclone as well on another server with snapdrive.