| Eric Lucas on 8 Mar 2013 13:21:59 -0800 |
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| Re: [PLUG] Booting from a RAID partition? |
I see... grub was only on one drive and it only knows one configuration - itself in the #1 (sda/hd0) location. When I blew that drive away... there went my only grub :-( Thanks. You and Rich just doubled my knowledge of grub. Maybe tripled. Eric On Fri, Mar 8, 2013 at 3:51 PM, David Kuntz <davkntz@gmail.com> wrote: > Eric, > See comments below: > > On Fri, Mar 8, 2013 at 3:11 PM, Eric Lucas <eric@lucii.org> wrote: >> >> I have a Red Hat 5.x box with RAID (software) mirroring: >> Two drives, sda and sdb >> >> /dev/md0 /boot (/dev/sda1 and /dev/sdb1) >> /dev/md1 / ( /dev/sda2 and /dev/sdb2) >> /dev/md2 <swap> ( /dev/sda13 and /dev/sdb3) >> /dev/md3 /home (/dev/sda4 and /dev/sdb4) >> >> When I remove sda and replace it with a blank drive (partitioned and >> formatted) the system is unable to boot. >> I get the normal grub menu but after hitting the return key I get: >> >> > root (hd0,0) > > hd0 is most likely /dev/sda, which is now missing. Try substituting hd1 and > see if that works. > > >> >> > Filesystem type is ext2fs, partition type 0xfd >> > kernel /vmlinuz-2.6..18-164.el5 ro root=/dev/md1 rhgb quiet >> > crashkernel=64M@48M >> > >> > Error 15: File not found >> > >> > Press any key to continue... >> >> >> When I remove sdb and replace it with a blank drive (partitioned and >> formatted) the system is unable to boot - it tries the CD/DVD device >> and then just sits there... no grub. >> > > It sounds like grub is only installed on /dev/sdb. Try running grub-install > /dev/sda and ensure there is an entry for both sda and sdb in > /etc/grub/device.map. Once grub is on sda, pull sdb and test. > >> > >> >> I expect that RAID mirroring should work with only one drive.... isn't >> that the idea? >> Should it NOT boot from a RAID drive but instead just have two >> identical /dev/sd0 boot partitions NOT in RAID? >> >> TIA >> Eric > > > RAID should work just fine with /boot on /dev/md0. I used to do it on a > bunch of servers at my old gig - saved my bacon a couple of times. But > booting while missing one of the drives in the mirror can get tricky, and > it's far better to just replace the drive while everything is up and > spinning :-D > HTH > David > >> >> >> ___________________________________________________________________________ >> Philadelphia Linux Users Group -- >> http://www.phillylinux.org >> Announcements - >> http://lists.phillylinux.org/mailman/listinfo/plug-announce >> General Discussion -- >> http://lists.phillylinux.org/mailman/listinfo/plug > > > > ___________________________________________________________________________ > Philadelphia Linux Users Group -- http://www.phillylinux.org > Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce > General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug > ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug