> I've got a four disk RAID5 setup on one controller. I want to add
> another controller, but am unsure of what strategy I should adopt to
> maintain the RAID integrity.
>
> As the order that the disks are found and identified as sda, sdb etc.
> determines the RAID structure and depends on the disk ID's, how do I
> maintain this when I put two of them on a different controller with
> different ID's.
>
> I'm a bit cautious here as I've had a bad experience when experimenting
> with disk changing and ended up with a corrupted array.
>
> It would be nice if Jacob's great HOWTO included this sort of info and
> also how to recover a snarled up array.
>
I'd do this:
take the highest scsi id numbers of your drives and put them (unchanged)
on the new controller which should be SECOND in the module load and pci
load sequence.
the linux will look at the drives like this:
scsi_hostadapter0
/dev/sda
/dev/sdb
scsi_hostadapter1
/dev/sdc
/dev/sdd
If I'm wrong here someone please correct me.
thanks
-sv
