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Recently, I decided to organise my partition scheme differently. Before I apply the changes on my physical machine, I decided to test it virtually, and met a little problem with GRUB.

Let me give you some information first. There is the scheme I plan to deploy :

  • / (primary), JFS, 40G (2GB on the virtual machine)
  • /boot (primary), ext2, 500M (200MB on the virtual machine)
  • /home (logical), ext4, 200G (8GB on the virtual machine)
  • /srv (logical), ext4, 5G (200MB on the virtual machine)
  • swap (logical), 4G (512MB on the virtual machine)

The new distribution will be Arch Linux, 64 bits (32 bits on the virtual machine). I successfully installed the new system on the virtual machine, but on reboot, GRUB seems to have a problem due to the JFS root partition : it cannot find several files in /boot/grub/i386-pc (mods, such as relocator or all_video).

At first, I thought it was due to the separate boot partition, but the problem persists if I include it in the primary root. However, when I use an ext4 for the / partition, GRUB loads perfectly.

It may be a problem with GRUB handling JFS partitions, however I remember that the GNU GRUB project applied a patch to fix this issue a while ago. As another test, I've created the same structure, but using ext4 instead of JFS for / : GRUB loads correctly.

Is there any specific configuration to be applied for GRUB to load a JFS partition without problems ?

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up vote 0 down vote accepted

Try adding ro to your grub commandline.

Take a look at the gentoo docs:

If your root filesystem is JFS, you must add " ro" to the kernel line since JFS needs to replay its log before it allows read-write mounting.

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I'm afraid I faced a mystery there... I was going to try adding ro, so I reinstalled another virtual machine and "ro" was already there in grub.cfg... I set (in the order) / (jfs), /boot (ext2), /home, /srv (ext4) and a swap, and it worked fine... – John WH Smith Jun 27 '13 at 15:50
Too bad we wont find out :/ – flob Jun 27 '13 at 16:45

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