Here are the direct links to responses -- still working out the post issues....
From Rick Joos - http://communities.netapp.com/message/16749#16749
There aren't really any downsides to letting SnapDrive do it automatically.
The ability to do manual igroup management was added for people that want to be able to specify particular igroup names, etc... .
The unique LUN IDs is not really a SnapDrive "issue" but storage system topic. On an active/active (or clustered) storage system, the LUNs IDs do have to be unique since the LUNs are available across the ports on both controllers with the same WWNodeName across controllers. When mapping LUNs the storage system checks if the number (the N in LUN) is already used for that igroup and only allows unused numbers.
Cheers,
Rick
From Brad Garvey - - http://communities.netapp.com/message/16793#16793
The replies above regarding LUN IDs are good points. But focusing from a pure iGroup perspective Rick is correct, I can't really think of any down sides to letting SnapDrive control this automatically unless you really need to manually control the iGroup names in your environment.
Thanks so much!
Terri Peluso
Senior Community Program Manager