Ugo Bellavance wrote:
jancio_wodnik@xxxxx wrote:
Christopher Chan pisze:
grub cannot find its second stage. Are you booting from a
mirrored partition?
Yes
What could be a solution? And what could have happen upon the reboot?
That is weird. I just re-installed centos5 and it is now booting
properly. What could I do to avoid this situation in the future?
IIRC, RHEL4 does not properly handle installation of grub on mirrored
partitions and therefore Centos4 suffers from the same problem.
RHEL5 does it properly now as you can see. This has been a long
outstanding problem of anaconda.
Yeap, this is true. After installing centos4 on RAID1 disk (software
raid) i always do:
grub
grub>device (hd0) /dev/hdc
grub>root (hd0,0) grub>setup (hd0)
where /dev/hdc is second RAID DISK (it could be whatever: /dev/sdb1 etc)
So system is booting form first or second riad1 disk
Ok, so to sum up from what I understand of my problem:
Installation of CentOS4 -> Installs grub only on one HDD partition out
of 2, in the mirror.
Well, I believe you chose md0 or something to install grub on right?
One disk fails, the one that has grub
Not necessarily. All it takes is a change in the sequence of disk
assignment.
System won't boot because it can't find grub on the other drive.
Correct. It needs to be instructed to look on its own drive.
If I had centos5 there in the first place, the setup would have taken
care of installing grub on the 2 mirrored raid partitions.
Am I right?
Yes.
Is there a way to know where grub is installed? I have a few servers
running in RAID 1 software for /boot, I gotta fix this. If I can't tell
whether it is installed or not, is it dangerous to re-install it using
the command above?
So long as you have all the necessary grub files, there is not much
danger. Even if you are missing a config file on this side of the mirror
(impossible...) so long as you load grub stage 2, you will have the
power you need to continue if you have access (eg: via serial)
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
