I've done a fresh install on a new system with 2 SATA drives, Seagate 80GB each. This is the first time I've done an installation where I used software raid to provide mirroring capability to the system. The raid is level 1 for mirroring. I used the installation documention on RedHat's enterprise site to go thru the installation/configuration for this. I didn't receive any errors during the installation, but after the system boots grub issues the following messages:
================================================================================ grub loading stage1.5.
Error 15 ================================================================================
Using the anaconda graphical installer, I've partitioned the drives as follows:
/dev/sda /dev/sdb
/dev/sda1 100mb /dev/md0 /boot /dev/sda2 76215mb /dev/md1 LVM VolGroup00
/dev/sdb1 100mb /dev/md0 /boot /dev/sdb2 76215mb /dev/md1 LVM VolGroup00
VolGroup00 76192mb LogVol00 swap 2048mb LogVol01 /root ext3 20480mb LogVol02 /home ext3 20480mb
During my research into the error above, it appears as though grub cannot find the /boot partition to continue loading the subsequent stages. I'm hoping to find some general help from the list if possible.
A couple of questions come to mind. Can grub boot off of a raid defined partition? If yes, what magic incantations would be appropriate? If no, should I just revert to a bare ext3 partition and don't implement raid on /boot?
Relavant parts of /boot/grub/grub.conf are:
default=0 timeout=5 splashimage=(hd0,0)/grub/spalsh.xmp.gz hiddenmenu title CentOS-4 i386 (2.6.9-22.EL) root (hd0,0) kernel /vmlinuz-2.6.9-22.EL ro root=/dev/VolGroup00/LogVol01 initrd /initrd-2.6.9-22.EL.img
And this is CentOS 4.2.
On Mon, 2006-01-16 at 20:59, Keith Morse wrote:
A couple of questions come to mind. Can grub boot off of a raid defined partition?
No, but with RAID1 it doesn't matter, since it can use either of the mirrored partitions.
If yes, what magic incantations would be appropriate? If no, should I just revert to a bare ext3 partition and don't implement raid on /boot?
Centos doesn't install grub correctly for RAID. Just do the install by hand: http://www.dirigo.net/tuxTips/avoidingProblems/GrubMdMbr.php You may have to experiment to see how to make the second drive boot if the first one fails. With SCSI, the drives shift up in both the grub and linux device names. With IDE they don't. I'm not sure about SATA. In the worst case you could change the cable and repeat the grub install procedure if you get the 2nd drive wrong and your primary fails.
Les Mikesell wrote:
Centos doesn't install grub correctly for RAID. Just do the install by hand: http://www.dirigo.net/tuxTips/avoidingProblems/GrubMdMbr.php You may have to experiment to see how to make the second drive boot if the first one fails. With SCSI, the drives shift up in both the grub and linux device names. With IDE they don't. I'm not sure about SATA. In the worst case you could change the cable and repeat the grub install procedure if you get the 2nd drive wrong and your primary fails
I had to boot into rescue mode from the cd and chrooted the environment. Followed the example from the link above and it fixed the problem. Many thanks. I've been pretty lucky with grub these last couple of years and haven't had to delve into it this deeply before.
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Keith Morse -
Les Mikesell