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Stack Same Path warning... recabling advice.

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:

1d, 1c

3d, 3c

11b, 11a

4d, 4c

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:

1d, 3c

3d, 11a

11b, 4c

4d, 1c

What will be the best approach on recabling them? Total shutdown? anything else need to be done on the OS level?

Thanks,

md

Re: Stack Same Path warning... recabling advice.

Keep in mind that most cards (including the onboard ports) have one ASIC chip for two ports, 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. You have a lot of choices.

Re: Stack Same Path warning... recabling advice.

hi, could you please elaborate on why it is not advisable to use A&B or C&B?

Re: Stack Same Path warning... recabling advice.

You are looking for the A&B modules of the disk shelf. I don't understand what you mean by C&B.

For example:

PRIMARY  PORT  SECONDARY PORT SHELF BAY

-------- ----  --------- ---- ---------

4a.24.0   B    3a.24.0    A    24    0

4a.24.1   B    3a.24.1    A    24    1

4a.24.2   B    3a.24.2    A    24    2

In this example B module is the primary and A is the secondary.

Re: Stack Same Path warning... recabling advice.

Hi,

I was just responding to your statement

"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.

Re: Stack Same Path warning... recabling advice.

Typo, I meant ports A&B are on one ASIC and ports C&D another ASIC.

Re: Stack Same Path warning... recabling advice.

thanks for clarifying. I heard that advise somewhere also but not so sure the reason behind it.

If I change the redundanth path, will I need to do anything else or will it be auto-detected without interruption.

Thanks,

md

Re: Stack Same Path warning... recabling advice.

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.

Re: Stack Same Path warning... recabling advice.

Hi,

in your sample above, B module is the primary. What determines between A and B module as to which becomes the primary and the redundant?

Re: Stack Same Path warning... recabling advice.

I guess I am now confusing the primary and secondary to the cable redundancy. The primary is the module connected to the owner of the disk. is that correct?