Raid 1 (Mirror) Question

[ChrisC]

Hello,

I was wondering if anyone could clear up a question about raid 1. Say I had 4 drives (C for OS/programs and D for data with their mirrors).

What I need to know is what happens when I swap one of the D drives for a completely different hard disc with different data in it.

Now that the 2 D drives have different data how does the computer proceed? Is there a Master slave relationship between the drive and its mirror so that it always mirrors the master?

Any help is appreciated ,

cheers
Chris

[Steve]

It depends on the implementation of RAID 1 I think.

If the new disk was built with different RAID hardware (or software if we're talking the stuff running on most motherboards) then it probably won't be recognised as part of the array, and the mirror will enter a critical state.

Supposing the disk is recognised as a mirror, then I guess there could be a situation where it would take over as master and start overwriting the other. However, I think it's more likely that it will be recognised as a mirror from a different array, and you'll have an extra mirror in your system... so you'd have two critical arrays.

Ultimately, however, it's hard to say, as I'm sure different implementations deal with such things differently.