3 Replies Latest reply on Oct 11, 2005 9:27 PM by 230263

    BOOT PROBLEM:   GRUB Loader stage2

    423100
      I installed RHE AS E 3, the server has 2 HD' s and I configured him in RAID 1 using the following partitions:

      #cat /proc/partitions

      major     minor     name     size

      9     0     md0     100 MB
      9     1     md1     15 GB
      9     2     md2     2 GB
      9     3     md3     52.9 GB
      8     0     sda     70 GB
      8     1     sda1     100 MB
      8     2     sda2     15 GB
      8     3     sda3     2 GB
      8     4     sda4     1 (partition extended)
      8     5     sda5     52.9 GB
      8     16     sdb     70 GB
      8     17     sdb1     100 MB
      8     18     sdb2     15 GB
      8     19     sdb3     2 GB
      8     20     sdb4     1 (partition extended)
      8     21     sdb5     52.9 GB

      and the RAID remained thus:

      #df

      Filesystem     Mounted on
      /dev/md1     /
      /dev/md3     /Datos
      /dev/md0     /boot

      #cat /proc/swaps
      /dev/md2




      I had to test the correct operation of the RAID, asi that I removed physically the hard disk of the server, at the moment that copied some data files. The RAID functioned correctly, then I did:

      raidhotremove /dev/md0 /dev/sda1
      raidhotremove /dev/md1 /dev/sda2
      raidhotremove /dev/md2 /dev/sda3
      raidhotremove /dev/md3 /dev/sda5

      Subsequently I resumed and I introduced the hard disk. Later I did the following thing:

      mdadm /dev/md0 -a /dev/sda1
      mdadm /dev/md1 -a /dev/sda2
      mdadm /dev/md2 -a /dev/sda3
      mdadm /dev/md3 -a /dev/sda5

      Once the hard disks were synchronized, I resumed and the following legend appears:

      GRUB Loader stage2
      >


      But when predicament any key appears me a new one line:

      GRUB Loader stage2
      >

      How can I correct this?, someone can help me?

      Greetings
        • 1. Re: BOOT PROBLEM:   GRUB Loader stage2
          230263
          I don't believe Grub understands software raid devices. It can no longer find you kernel. You can manually tell grub were to boot from by telling it what you root(boot) device is
          root(sd1,1)
          then tell it what kernal and where your root filesystem is (your kernel might be different grub will to tab completion though so just type kernel/vmlin(tab key)
          kernel /vmlinuz-2.4.21-27.0.2.EL ro root=/dev/md1
          and then where your initial ram disk is
          initrd /initrd-2.4.21-27.0.2.EL.img
          Then boot away
          boot
          After you boot you will need to update the boot sector assuing that /etc/grub.conf looks correct
          #>grub /dev/sda
          #>grub /dev/sdb
          • 2. Re: BOOT PROBLEM:   GRUB Loader stage2
            423100
            I reboot with CD-ROM and type this:

            root (hd0,0)
            setup (hd0)

            Because with:

            grub> root (sda)
            Error 23: Error while parsing number
            grub> root (sda0)
            Error 23: Error while parsing number
            grub> root (sda1)
            Error 23: Error while parsing number

            and then

            kernel /vmlinuz-2.4.21-32.EL ro root=/dev/md1
            initrd /initrd-2.4.21-32.EL.img
            boot

            and finally this:
            grub /dev/sda
            grub /dev/sdb

            but with both cases, I had

            with grub /dev/sda:

            root (hd0,0)
            setup (hd0)

            grub /dev/sdb

            root (hd1,0)
            setup (hd1)

            and not working, I reboot and enter the GRUB I have type kernel /vmlinuz..... etc...

            The /etc/grub.conf files is:

            [root@ml150linux root]# cat /etc/grub.conf
            # grub.conf generated by anaconda
            #
            # Note that you do not have to rerun grub after making changes to this file
            # NOTICE: You have a /boot partition. This means that
            # all kernel and initrd paths are relative to /boot/, eg.
            # root (hd0,0)
            # kernel /vmlinuz-version ro root=/dev/md1
            # initrd /initrd-version.img
            #boot=/dev/sda
            default=0
            timeout=10
            splashimage=(hd0,0)/grub/splash.xpm.gz
            title Red Hat Enterprise Linux AS (2.4.21-32.ELsmp)
            root (hd0,0)
            kernel /vmlinuz-2.4.21-32.ELsmp ro root=/dev/md1
            initrd /initrd-2.4.21-32.ELsmp.img
            title Red Hat Enterprise Linux AS-up (2.4.21-32.EL)
            root (hd0,0)
            kernel /vmlinuz-2.4.21-32.EL ro root=/dev/md1
            initrd /initrd-2.4.21-32.EL.img
            [root@ml150linux root]#

            What more I can do???


            Thanks
            • 3. Re: BOOT PROBLEM:   GRUB Loader stage2
              230263
              It's not
              grub> root(sda)
              but
              grub> root(sd1,1)
              Look back at my original post. The problem you are having is not that your grub.conf file is missing, but that grub (the boot loader) cannot find it. When the boot loader is installed it stores the physical location of your config file and puts that info in the boot sector. If you move the grub.conf around (change the physical location not directory location) the boot loader can no longer find it.

              You could also try booting to the cd and type
              linux rescue
              at the prompt
              have it boot and mount you hard drives and then try running
              make sure that /boot/grub/gub.conf looks correct then
              #>grub-install /dev/sda
              #>grub-install /dev/sdb