2012-12-10 07:59 AM
Are there any best practices regarding SAS disk ownership with DataONTAP 8 (7-mode) with HA controllers?
I tend to assign all disks in a shelf to the same controller where the balance of disks between the controllers allows this. I know that you don't need to do this and was wondering if there was some documented best practice; I am anable to find any. My thoughts were that if in the very unlikely event that I lost a shelf then only the aggregate(s) on controller owning the disks in that shelf would be affected. Also, it often means that I can rack the storage with the controllers in the middle of the rack and then assign all of the disk shelves bellow them to the bottom controller and all of the shelves above them to the top shelf.
2012-12-10 12:39 PM
installation best practices in Germany is that you assign the upper shelfs to the upper controller an the bottom to the bottom controller. Best with to seperate stacks. In the real world, especially on small systems with low disk count sometimes the disks in one diskshelf spread to 2 different controller.
If there 2 seperate stacks one controller is owning all of the disks of the stack the disk.auto_assign option is working well. Otherwise you have to assign the disks manually when RMA disks arrived.