Re: how does GRUB read from /boot on software-RAID partition?
On Tue, 24 Feb 2009 17:14:54 -0500
"Barclay, Daniel" <daniel@fgm.com> wrote:
> Jack Schneider wrote:
> > On Tue, 24 Feb 2009 15:21:23 -0500
> > "Barclay, Daniel" <daniel@fgm.com> wrote:
> >
> >> Eduardo M KALINOWSKI wrote:
> >>> Barclay, Daniel wrote:
> ...
> >>>> ... is GRUB taking advantage of the fact that the RAID metadata
> >>>> is written at the end of a partition ...
> >> ...
> >>>> If so, how reliable is that?
> >>>>
> >>>> Should one put /boot on a plain, non-RAID partition on one disk
> >>>> and ...maintain a backup /boot partition on
> >>>> the second disk, or is it fine to put /boot on a mirrored
> >>>> partition (so maintaining redundancy is automatic) and let GRUB
> >>>> read the partition directly?
> >>> ... why make things more complicated and not automatic?
> >> ... I _am_ trying to avoid the
> >> complicated and non-automatic solution (trying to check whether the
> >> simpler solution is reliable).
> ...
>
> > Hi, Daniel et al
> >
> > The following is an outline of my setup on a couple of the system
> > disks.
> >
> > Roughly I have two md devices for the host system, md0 & md1:
> >
> > jack@host:~$ df -m
> > Filesystem 1M-blocks Used Available Use% Mounted on
> > /dev/md0 9389 7157 1755 81% /
> > tmpfs 4005 1 4005 1% /lib/init/rw
> > udev 10 1 10 2% /dev
> > tmpfs 4005 0 4005 0% /dev/shm
> > /dev/dm-0 40318 11628 26642 31% /home
> > /dev/dm-4 19686 15356 3331
> > 83% /home/jack/XP_VDI /dev/dm-6 30238 7453
> > 21250 26% /home/jack/suse /dev/dm-2 3024
> > 70 2802 3% /tmp /dev/dm-1 8064
> > 3426 4229 45% /var /dev/hda 90
> > 90 0 100% /media/cdrom0
> >
> > The only concern I have is that / is marginally small. It's
> > expandable tho.
> > /boot is just on /mdo. I have run without incident for over a year.
>
> But if you haven't had any disk-failure incidents, do you know whether
> your setup will reliably work if either disk fails? (Did you mean
> that you simulated disk failure?)
>
>
>
> Daniel
Hi, Daniel
Sorry, no failures to date. My thinking was since I was running testing
I didn't want updates/bugs/my ineptitude to trash my data and other
OS. This config allows me to change easily... of course I'm a Debian
nooby. I can boot from either disk. I pulled a sata cable from one.
Jack
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