Arch Linux

timm

Member

From: Wisconsin

Registered: 2004-02-25

Posts: 417

Can't find root device

I'm running arch on a machine with older hardware, and recently (perhaps after a system upgrade) it stopped being able to boot.  This thing generally sits in a corner in my basement administered via ssh, so if it isn't running for a few days I may not even notice.  I tried to ssh to it the other day and it didn't answer, so I noticed.

The main drive is a pata drive, there are also a couple sata drives that are on a promise controller.  I boot from the pata drive.

When I try to boot, everything looks ok until I get:

Waiting 10 seconds for device /dev/disk/by-uuid/lotsofnumbers ...
Root device '/dev/disk/by-uuid/lotsofnumbers' doesn't exist.  Attempting to create it.
ERROR:  Unable to determine major/minor number of root device '/dev/disk/by-uuid/lotsofnumbers'
You are being dropped to a recovery shell
     Type 'exit' to try and continue booting
/bin/sh: Can't contact tty;  job control turned off
[ramfs /]#

At this point I have no keyboard input and have to reboot.

I booted with the arch cd and chrooted into my installation (which shows up on /dev/hda1, 2, 3, etc). Everything appears to be there.  I checked mkinitcpio.conf and made sure everything looked right there, reran mkinitcpio, no improvement.  I went back into the chroot and did a full pacman update, no improvement.

I would appreciate any suggestions.

[edit]
Found this thread http://bbs.archlinux.org/viewtopic.php?pid=728539 after I posted, so back to the basement...

[edit]

That didn't pan out.  grub uses (hd0,0) and the boot system if correctly found there.

[edit]

Appears that this has been reported as a bug here: http://bugs.archlinux.org/task/18810

Last edited by timm (2010-04-02 18:01:29)

demian

Member

From: Frankfurt, Germany

Registered: 2009-05-06

Posts: 709

Re: Can't find root device

I had the same problem as you.
Booting with root=/dev/sda5 instead of root=/dev/disk/by-uuid/bunchofnumbers fixed it for me.

Regards,
demian

Last edited by demian (2010-04-04 09:25:54)

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no place like /home
github

timm

Member

From: Wisconsin

Registered: 2004-02-25

Posts: 417

Re: Can't find root device

I've tried a couple variations on that, will try others.  When I boot with the arch live cd, the root partition comes up as sde2, so I've tried that, together with sda2, hda2, etc.  However, I haven't been systematic about figuring out where arch is putting that partition on a boot from the hard drive. (although it starts to boot with grub set to (hd0,0), so I'd expect it should be sda2.)

Leonid.I

Member

From: Aethyr

Registered: 2009-03-22

Posts: 999

Re: Can't find root device

Quite a puzzle...

Just to make sure, you did boot with the fallback kernel, right?
Also, are you able to retrieve lates dmesg.log/kernel.log from the hard drive, to see the naming of partitions and UUIDs?
FInally, does downgrading of the kernel/udev help?

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Arch Linux is more than just GNU/Linux -- it's an adventure
pkill -9 systemd

timm

Member

From: Wisconsin

Registered: 2004-02-25

Posts: 417

Re: Can't find root device

I did boot with the fallback.  If I chroot and look at dmesg, it tells me the partitions are named sg1, sg2, etc.  Using that designation does not change anything.  My last successful boot shows my root drive as hda2 (this in kernel.log.2)  That doesn't work for boot now.

My latest kernel.log has the following entries:

kernel: Disabling lock debugging due to kernel taint
kernel: Machine check events logged

I tried downgrading udev and the kernel, and did so successfully to kernel26-2.6.32-9.1 and udev-151-2 but this didn't change anything.  I tried to downgrade farther but the udev download complains about gstreamer0, which complains about gstreamer-something else, and I don't know how far I can safely go downgrading these packages without running into more problems.