I am getting "Stack Same path" warning when running Config Advisor. This is because of the connectivity of the primary and redundant path on four stack of FC shelves look like this:
I guess what this means, is if the module (example IOM on port 1 where 1d and 1c) breaks, then I lose the entire stack, am I right? potential loss of data? especially since we are using software base ownership (disk assign)
I plan to recable them, but I want to learn more, but I plan to recable them like these:
What will be the best approach on recabling them? Total shutdown? anything else need to be done on the OS level?
"you shouldn't use A&B or C&B ports from the same card on one controller.You might find easier to cable them using same port such on two different cards, for example 1a/3a, 4a/11a partner could be 1b/3b, 4b/11b".
I understand the part where you say that I should use port a on different cards. I thought you were saying that I should not use port 'a' on one card, then port 'c' on another card.
Once you verify MPHA you should be able to move cables without down time. Do it slowly, one cable at a time then make sure everything is working before moving another cable, storage show disk -p before each move.
I know people at NetApp struggled with MPHA at first; the concept is difficult to understand at first, once you have worked with it for a while it will make sense. The link you have is about the best explanation you will find; the diagrams are very good at the end of the article. The old shelves had IN/OUT on the modules; they changed at some point to arrows.
If you send me you layout I might be able to help more. Let me know the type of modules you are using in each stack. We have a lot of equipment onsite, I can send pictures if that helps.
You can always get NetApp PS services to help you with this, I'm sure they will charge for this.
I would use the same controller ports, Controller 1 connects to stack 1 A IN on controller port 1a and B out would be port 3a on controller 1. Controller 2 would connect to stack 1 A OUT on 1a and port 3a for B IN on the last shelf of the stack 1. To verify this storage show disk -p on both controllers, during downtime you should be able to pull module A on shelf 1 stack 1 and both systems should stay up, you will see errors messages after a few minutes. Re-insert the module after a few minutes and check the MPHA again.
Thanks again. six of our stacks are saying " primary and redundant are on the same path" Just by running show disk -p, I can see that they are either both on A or both on B module. On top of that both cables are connected to the same ASIC on the controller (example: 1a, 1b) So they are two issues it seems. What do you think is the best approach in terms in order in which of these issue I should first? should I separate module connectivity first or the ASIC connectivity?