Select MU during BC config on XP1024

[Jim Turner]

Hi folks,

I've searched the TKB, searched the forums, and done some general googling, but I still can't find a definition for "Mirror Unit".

In terms of Business Copy on an XP1024, would someone be so kind as to explain the significance of "Select MU" (choices are 0, 1, or 2) when creating new BCV P-Vol/S-Vol pairs in command view xp?

Thanks,
Jim

[Jim Turner]

I actually figured this one out myself. Let's use the following CU:LDEV addresses for example:

04:00
05:00
05:01
05:02

We'll make the first BC pair 04:00 and 05:00 with the former being the P-Vol and the latter being the S-Vol. This first pairing is Mirror Unit 0 or "MU0".

To be safe, I want a second Business Copy volume of the same data. I can make a second BC pair using 05:00 as the P-Vol and 05:01 as the S-Vol. This "second-generation" pairing is MU1.

The trifecta is achieved with third copy of the same data via a third BC volume. I make my third BC pair using 05:01 as the P-Vol and 05:02 as the S-Vol. This third-generation pairing is MU2.

To Summarize:

04:00--MU0--05:00
............05:00--MU1--05:01
........................05:01--MU2--05:02

where the first CU:LDEV of each pair is the P-Vol and the second CU:LDEV of each pair is the S-Vol.

Maybe it was in the XP docs and I just missed it. I don't know. At least it's here now and searchable in case someone else has the same question later.