Hi there,
Is anyone using "root=LABEL=xxxx" grub.conf, please? Anyone also using
ext4 for their root?
I can find numerous references to this syntax going back to 2005 or
so, and some major distros seem to use it as the default way of
describing "root=" to the kernel.
http://www.linuxforums.org/forum/redhat-fedora-linux-help/23010-root-label-grub-conf.html
http://linux.derkeiler.com/Mailing-Lists/RedHat/2005-01/0026.html
But it doesn't work for me. :(
Here's a working configuration:
strol...@hex ~ $ cat /etc/fstab
# /etc/fstab: static file system information.
#
# <fs> <mountpoint> <type> <opts>
<dump/pass>
# NOTE: If your BOOT partition is ReiserFS, add the notail option to
opts.
LABEL=boot /boot ext2 noauto,noatime
1 2
LABEL=root / ext4 noatime
0 1
LABEL=swap none swap sw
0 0
/dev/cdrom /mnt/cdrom auto noauto,ro
0 0
# glibc 2.2 and above expects tmpfs to be mounted at /dev/shm for
# POSIX shared memory (shm_open, shm_unlink).
# (tmpfs is a dynamically expandable/shrinkable ramdisk, and will
# use almost no memory if not populated with files)
shm /dev/shm tmpfs
nodev,nosuid,noexec 0 0
strol...@hex ~ $ sudo mount -v -L boot
/dev/sda1 on /boot type ext2 (rw,noatime)
strol...@hex ~ $ cat /boot/grub/grub.conf
default 0
timeout 30
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
title Gentoo Linux 2.6.28-gentoo-r1
root (hd0,0)
kernel /boot/bzImage-2.6.28-gentoo-r1 root=/dev/sda6
strol...@hex ~ $
If I simply change the kernel line of grub.conf to:
kernel /boot/bzImage-2.6.28-gentoo-r1 root=LABEL=root
Then I get a kernel panic upon boot:
VFS: Cannot open root device "LABEL=root" or unknown-block(0,0)
Please append a correct "root=" boot option; here are the
available partitions:
...
Kernel Panic - not syncing: VFS Unable to mount root fs on unknown-
block(0,0)
Full screenshot of kernel panic:
http://stuff.stroller.uk.eu.org/KernelPanic.png
Googling this error brings up quite a number of hits, and I reckon I
must have spent a couple of hours now trying the most popular
resolutions. This is quite a minor error - if I wasn't such an
obsessive-compulsive I could easily ignore it, but I am, and it's
frustrating the heck out of me.
One forum thread / bug report suggests the ata_piix module is to
blame, but compiling that statically into my kernel doesn't help.
http://www.linuxquestions.org/questions/fedora-35/fc2-vfs-cannot-open-root-device-label-or-unknown-block00-269230/
https://bugzilla.redhat.com/show_bug.cgi?id=126953
Another post (can't find the reference now) suggests disabling
"Initial RAM filesystem and RAM disk (initramfs/initrd) support" but
that doesn't make any difference, either.
Finally, this thread <http://kerneltrap.org/node/2318> says "check
your .config and look for CONFIG_BLK_DEV_IDE and
CONFIG_BLK_DEV_IDEDISK entries." This is quite an old post, however,
and these options aren't available in 2.6.28 (from my distro); I
enabled CONFIG_BLK_DEV_IDEPCI instead, but it has no positive effect.
I had better mention that I am using a 3ware 9500 RAID controller on
the PCI bus. I suspect the problem is specific to this (and my
combination of modules / compiled-in kernel drivers), but I thought I
would throw the question out there & see if any other ext4 users had
also seen the same thing.
Thanks in advance for any suggestions,
Stroller.
