"umount: devfs: not mounted"

[bmoore]

I've installed Knoppix 3.7 onto a second hd, have Lilo working fine, but as KDE loads, Knoppix hangs at "umount: devfs: not mounted." I've scoured the web, but with no definitive answers, just a lot of stuff about recompiling my kernel. Help, please?

[mr_ed]

Well, since you're not getting any takers, here are some not-so-helpful observations.

The problem is most probably not what that error message is telling you, for three reasons. The first is that it's not a fatal error to unmount (umount) a file system that isn't mounted. Chances are that the script that called umount just did it to make absolutely sure that devfs was unmounted.

Then there's the general situation that when something hangs, it's often hanging on some step after the one that you last got a message about. The step that hangs ... is hung. It usually won't be able to send an error message.

Finally, when a process goes through steps A, B, C, D, E, F, and then blows up on step G, it's just one of Murphy's Laws that the real problem occurred back in step B, C, or D, but the consequencies of that problem didn't show up until later.

I've done a little poking around in Knoppix to try to find the script that could be bombing on you, but no luck so far. Can you tell us more about what you see before things hang?

-- Ed

[bmoore]

Firstly, thanks for taking this up... for a while I though I had bad breath. Secondly, what you suggested is what I figured. The startup process runs through most of it's stuff, but when trying to run the 2.4 kernel hangs at the unmount; with the 2.6 kernel, at kjournald process. All the other posts in other forums discussed the default setting of the kernel being to not allow devfs and apparently I need to. Right now, I've been relegated to trying a new compile. I got a compiling linux for dummies article which I'm going to play with when I have time. Thanks, again... any ideas you have would be greatly appreciated.

[mr_ed]

for a while I thought I had bad breath
If that's the problem, recompiling the kernel won't help! :D

I think I found where in the boot process your system is hanging. Please check these message fragments to make sure I'm in the right place.
2.4.27 kernel
RAMDISK: Compressed image found at block 0
Freeing initrd memory: 3185k freed
VFS: Mounted root (ext2 filesystem).
Freeing unused kernel memory: 144k freed
initrd-tools: 0.1.74
mount: fstype devfs not supported by kernel
Journalled Block Device driver loaded
umount: devfs: not mounted
x=x=x=x=x (or below)
mount: fstype devfs not supported by kernel
kjournald starting. Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
umount: devfs: not mounted
x=x=x=x=x (or above)
INIT: version 2.78-knoppix booting
Welcome to KNOPPIX (HD-Installation)
2.6.9 kernel
RAMDISK: Compressed image found at block 0
VFS: Mounted root (ext2 filesystem).
Freeing unused kernel memory: 276k freed
initrd-tools: 0.1.74
mount: fstype devfs not supported by kernel
EXT3-fs: mounted filesystem with ordered data mode.
kjournald starting. Commit interval 5 seconds
x=x=x=x=x
umount: devfs: not mounted
INIT: version 2.78-knoppix booting
Welcome to KNOPPIX (HD-Installation)

Up until that last line, "Welcome to KNOPPIX," the text is in monochrome. Any later references to devfs or kjournald will be in multi-color text.

What's happening in the middle of this stretch, at least on my computer, is that the root partition on the hard drive is being mounted as filesystem type ext3. The ext3 and reiserfs filesystems are more resistant to errors because they journal - keep logs of - the read and write activity to drives; ext2 doesn't do this.

So if this is where your system is hanging, that is, when it starts working with the root partition using a journalled filesystem, then my guess would be that the filesystem on that partition is bad (and devfs isn't involved).

What I'd do is run fsck on all the Linux partitions (except swap) on the drive. Even on any that are ext2, to help determine the extent and reason for the (possible) problem.
:shock: NOTE !!! :shock:

- do not run fsck on a mounted filesystem !!!

- $ man fsck before using !!!So what you do is boot from the Knoppix CD and do something like this:


$ sudo umount /dev/hda1
$ sudo fsck /dev/hda1
You can also run fsck from the hard drive if you have another Linux to boot into, but DO NOT run it on the partition that you're using. One way to do this accidentally is to type # fsck with no options, which makes it run on all the filesystems in /etc/fstab (which of course includes the one you're on).

That said, fsck does try to warn you before running on a mounted filesystem. But forewarned is forearmed - too bad Venus de Milo didn't hear that one in time! :D

Another thing you could do is just start the installation over. QTParted will reformat that partition for you, but just to check that there isn't maybe a bad spot on the drive I think I'd do this before running knoppix-installer:


$ sudo mkfs -c -t ext3 /dev/hda1
$ sudo fsck /dev/hda1
The -c option checks for bad blocks before writing the filesystem. The fsck is redundant, but hey - why not?

And skip recompiling the kernel, eh? :D

-- Ed

[bmoore]

Thanks Ed... I'm gonna try and work through this. I've already re-hd-installed an inordinate number of times, maybe next will be the lucky one.

[mr_ed]

You must have the patience of Job to keep re-trying Knoppix!

Have you tried installing another version of Linux? Debian's sarge is about my favorite - its installer works very well, and its hardware detection is almost as good as Knoppix'. Another one that goes very smoothly is Progeny Debian.

-- Ed