It worked! /sbin/grub-install /dev/md0 Thanks, Guy } -----Original Message----- } From: John Robinson [mailto:john.robinson@xxxxxxxxxxxxxxxx] } Sent: Tuesday, November 02, 2010 11:24 AM } To: Guy Watkins } Cc: 'Linux RAID' } Subject: Re: Upgraded grub, now confused about mirrored /boot } } On 02/11/2010 06:11, Guy Watkins wrote: } > Hello, } > } > I upgraded my system from Red Hat FC10 to FC11. The instructions } > say to run this command: } > /sbin/grub-install BOOTDEVICE } > } > And if it fails, run this: } > /sbin/grub-install --recheck /dev/sda } > } > However, my boot disk (/boot) is mirrored on 4 disks and I think (or } hope) } > all 4 are bootable. The mirrors were created at install time many years } ago } > when I installed FC5. No idea if it really made more than 1 bootable. } I } > have assumed that if sda failed, I could still boot from sdb, sdc or } sdd. } > And I do understand that I might need to remove sda first, depending on } the } > type of failure. Lucky for me, no drive has failed yet and I don't } recall } > if I tested booting off of any other disks. } > } > I do have this on the kernel line: } > md-mod.start_dirty_degraded=1 } > } > So, what do I do now? Run that command on all 4 disks? Or run it on } > /dev/md0? } } I don't know which grub version you get in FC10/11, but in CentOS 5 } (with grub 0.97), grub-install is a clever little script which does all } the work for you, so you just } /sbin/grub-install /dev/md0 } and it will install grub on all of /dev/md0's constituent drives and } generally get everything right. } } You should be fine with metadata 0.90 or 1.0 as both store the } superblock at the end of the device. 1.1 and 1.2 probably won't work } because their constituent partitions don't look like bare filesystems. } } What actually happens is that the BIOS boots off the first live disc, } and so does grub 0.97, neither has any inherent support for RAID but } they don't have to if it's a RAID-1 mirror because both (or all) parts } of the mirror can be used on their own, at least for reading enough to } boot with. } } You should probably test booting up with your first drive disconnected, } just to be sure! } } Cheers, } } John. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
