Re: raid1 bootable disks
A J Stiles wrote:
> end up configuring it to boot from sdb. But the way most motherboards work
> is that, if the first drive fails Power On Self Test, then it will be ignored
> and the second drive will be assigned as sda. So the bootloader on the
> second drive must be configured to boot from sda.
In my experience, what any random motherboard will do in the event of a
missing drive is completely unpredictable. Every manufacturer is
different, and different boards from the same manufacturer can behave
differently. Lately, with SATA drives, it seems that it is more common
for the drive's ID to be determined by which connector on the
motherboard (or add-on controller) it is plugged into. When we lose sda
on our HP servers, sdb remains sdb.
In any event, we've found grub boot floppies or boot USB sticks to be
invaluable. You boot from that and get a full grub console, where you
can direct the loader to boot from any available drive in the machine
and pass whatever root disk parameters are appropriate.
Always test you configuration before you put it into production.
Spending 20 minutes pulling sda from the machine and booting it up to
see what happens will tell you everything that you need to know.