From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040324 Galeon/1.3.14 Description of problem: After upgrading from RedHat 9 to Fedora Core 2, my system won't boot. It panics with the message: Kernel panic: VFS: Unable to mount root fs on unknown-block(0,0) How reproducible: Always Steps to Reproduce: 1. Upgrade to Fedora Core 2 2. Attempt to boot upgraded system Actual Results: Kernel panics. Here are the last 5 lines of output transcribed from my screen: Loading ext3.ko module Creating block devices VFS: Cannot open root device "LABEL=/" or unknown-block(0,0) Please append a correct "root=" boot option Kernel panic: VFS: Unable to mount root fs on unknown-block(0,0) Expected Results: Successful boot. Additional info: This install was tricky. I have an ASUS P4P800 motherboard so I had to use the ISO from comment #122 of bug #121819 to actually get the installer running. The install went pretty smoothly after that modulo two small oddities: First, I noticed that the installer thought that my HDD was "/dev/sda". RH9 called it "/dev/hdb", so I was a bit confused. I did some searches on Google, and found a bunch of pages which indicate that the 2.6 kernal often considers SATA drives to be SCSI. This is apparently okay though. The other oddity was that it couldn't find a boot loader installed. I told it to install GRUB. This seemed odd to me because I already had GRUB installed from my RH9 install. After the install, I can't boot because of the above-mentioned panic. Google turned up a number of people with similar problems (with various Linux distros) and possible solutions. These all involved tweaking the "root=" kernel parameter, or adding a "vdso=0" kernel parameter. I added the "vdso=0" param, and then I tried changing the root param to each of the following values (some are a bit off the wall, but I'm grasping at straws here...): LABEL=/ (this is what worked in RH9, and also what the FC2 installer put) /dev/hda3 /dev/hdb3 /dev/sda3 /dev/sdb3 303 343 803 813 All of them gave essentially the same panic message, modulo the (0,0) and "LABEL=/". My root volume is the third partition on the hard drive hooked up to the first SATA connector. (there are two SATA connectors, and two parallel connectors on my motherboard) This is the only HDD in the machine. It has three partitions: /boot, swap, and / (root). When I use the FC2 "rescue" boot I'm able to mount the root and boot from my SATA drive without any problems. 'df' reports that the root is /dev/sda3.
It looks like the problem was due to the initrd being incomplete. In particular, I think it was missing the ata_piix module. To fix this, I ran the following: mkinitrd --preload=scsi_mod --preload=sd_mod --with=ata_piix \ /boot/initrd.img-2.6.5-sata 2.6.5-1.358 and then I modified my grub parameters in two ways: - I changed the initrd line to refer to the output of the above command - I changed the root= option to use /dev/sda3 My system is now able to boot again. So there appears to be a problem in the way the FC2 installer constructs the initrd that it installs on some systems.
*** This bug has been marked as a duplicate of 121848 ***
Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.