Tony Mountifield wrote:
- Can a install grub on the replaced boot drive with the system still running?
Yes, after the /boot partition re-sync has completed, execute grub and:
root (hd0,0) setup (hd0)
And also:
root (hd1,0) setup (hd1)
quit
That will ensure both mirrored drives have GRUB in the MBR (the MBR isn't mirrored, only partitions are). Otherwise if hd0 fails, the system will be unable to boot from the good drive hd1.
See http://fedoranews.org/mediawiki/index.php/How_to_setup_and_manage_your_disk_...
Earlier in the thread, the OP said the 2nd mirror is on sde, not sdb, so this won't work for him and depending on his scsi controller, probably can't boot from that drive at all. In any case it is a good idea to know how to do a rescue mode boot from your install CD.