[CentOS] Mirroring Hard Drive
John R Pierce
pierce at hogranch.com
Sat Aug 2 20:03:46 UTC 2008
Bent Terp wrote:
> On Sat, Aug 2, 2008 at 4:00 PM, Johnny Hughes <johnny at centos.org> wrote:
>> stupid question ... why not just put it in the machine and make it a raid1
> cuz it's not an md volume to begin with?
one method is to make the 2nd disk a 'half' mirror, with all the same
partitions, then use dump|restore to copy your file systems over to it,
fix up the grub boot on it, edit teh fstab on this new volume to refer
to the md sets, then swap it and make it the primary drive, and add the
original drive as the mirror.
if uptime is your goal, don't forget to mirror the swap too. too many
people seem to think thats uneccessary, but if a drive containing
unmirrored swap dies, the system can only crash and burn (eg, panic).
now, do note, a mirror is ONLY good for protecting against physical
drive failure, and maintaining uptime, its /NOT/ a substitute for
backups, as a software glitch, or user error can wipe the mirror out
just as quick as can be.
More information about the CentOS