2015-07-22 09:20 AM
I have the following situation
FAS6290, CDOT 8.2.3
It has 2 mixed (SSD & SAS) stacks
- Stack #1: 4xDS2246x600GB SAS + 1xDS2246x200GB SSD (2 x sas cables to controller 1, 2 x sas cables to controller 2)
- Stack #2: 4xDS2246x600GB SAS + 1xDS2246x200GB SSD (2 x sas cables to controller 1, 2 x sas cables to controller 2)
SSD shelves are the first (last) of the stack in both stacks above.
I want to separate SSD and SAS shelves, splitting each of the stacks in 2, WITHOUT SHUTDOWN. That will end with 4 stacks (2 x SAS, 2 x SSD)
If I remove ONLINE the SAS cables between the SSD shelf and the first of the SAS shelves in each stack, will those 2 stacks be automatically converted in 4 stacks?
Can I then close these 4 stacks with 8 SAS cables going back to the controllers to restore the redundant connection?
It is clear I can do this WITH a shutdown, but can it be done WITHOUT?
2015-07-23 09:18 AM - edited 2015-07-23 11:31 AM
Thanks for your answer. I had already read this:
Hot-removing disk shelves in systems running Data ONTAP 8.2.1 or later
but I don't think it fits what I am doing, since I am not removing the shelf (all shelves remain connected to both controllers at any time)
May be the following quick hand-drawing makes it more clear.
In step #1, I remove 2 SAS cables, but the removal keeps all shelves connected (single path, instead of dual).
In step #2, I reconnect the 4 disconnected shelf SAS ports, but to new SAS ports in the controller.
It's clear I can power down the storage and do this changes offline, but can I do them without disrupting service?
2015-07-23 10:25 AM
2015-08-12 11:21 PM
That looks dicey. But I suspect odds of success would improve if you did a takeover/giveback between step 1 and step 2 so each node gets to boot in a dual stack single path ha config. Interesting lab experiment, but wouldn't try it on a production filer. If you do try it, tell us if it panics on you.