Hi Jochen,

SnapDrive is responsible for the mapping of LUNs to drive letters. But I would disconnect the LUNs with the help of SnapDrive first and than shutdown the filers to move them to the new building. Then power on the filers and connect the LUNs again. For conencting the LUNs again to the servers you have to take care which LUN is connected to which server and drive letter. In that case you will have less risk.

Just for fun I tested following in my lab:

- open the Computer Management and browse into the SnapDrive Disk tree - Windows server with 4 LUNs on Filer1 and 4 LUNs on Filer2 (automapping) - shutdown both Filer with halt -f - on the windows server I refresh the SnapDrive tree in the Computer Management -> SnapDrive hangs and I had to kill the mmc process -> reopen the Computer Management and browse to the SnapDrive tree -> no disk listed - Windows Server reports errors and warnings like:

*** {Delayed Write Failed} Windows was unable to save all the data for the file . The data has been lost. This error may be caused by a failure of your computer hardware or network connection. Please try to save this file elsewhere. *** The system failed to flush data to the transaction log. Corruption may occur. *** The device, \Device\Harddisk5, is not ready for access yet. ***

- power on both filer after some minutes - refresh the SnapDrive Disk tree -> All LUNs mapped again as before!

Hope that helps!

Mit freundlichen Grüßen / Best regards

Sebastian Wischer Junior Product Engineer Storage Systems FSC EP ST SYS 1 Fujitsu Siemens Computers Heinz-Nixdorf-Ring 1 33106 Paderborn Germany

Telephone: +49 5251 8 22239 Telefax: +49 5251 8 333 22239 Email: Sebastian.Wischer@fujitsu-siemens.com Internet: http://www.fujitsu-siemens.com

-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Willeke, Jochen Sent: Wednesday, July 19, 2006 10:15 AM To: NetApp Toasters List Subject: Mapping of LUN's in Windows

Hi toasters,

we want to move two Filers from one building to another. Due to this we need to have a SAN redesign, as those filers host our exchange data.

In our HBA configuration we have currently automapping. So possibly it could be that we have a WWPN with another SCSI ID after the change.

As we use snapdrive i suppose snapdrive to be responsible for the coordination of LUN's to driveletters. But i am not really sure, so i just want to ask some experts, if we can run into problems with wrong driveletters after the change.

Has anybody experience with this?

Best Regards and thanks in advance

Jochen