If you're planning on installing Linux kernel 2.6.25.4 or newer with SATA, beware. This past Friday I decided to upgrade my departmental workstations from Fedora 8 to 9 with preupgrade, and the process itself went extremely smooth compared to the three hours I spent trying to get the latest kernel update to boot. Fedora just released 2.6.25.4-10.fc8 this week, so as part of the upgrade I first made sure that FC8 was completely patched. Upon rebooting a found that once the kernel loaded after the bios my drive suddenly disappeared:

Unable to access resume device (LABEL=SWAP-sda2)
mount: could not find file system '/dev/root'
setuproot: moving /dev failed: No such file or directory
setuproot: error mounting /proc: No such file or directory
setuproot: error mounting /sys: No such file or directory
switchroot: mount failed: No such file or directory

Of course my first response was, "Freaking awesome!" Which I'm sure is a sentiment that would be shared by all. Subsequent posts to the Fedora mailing list and IRC chat room came up with nothing useful. Actually, that's not exactly true. One user responded with, "Why not just user your old kernel?" That has to be one of my favorite responses of all time. Another great response was, "Might not be related, but that kernel doesn't seem to be available yet, I just tried updating." Of course! That has to be it. For some reason my locally maintained yum mirror must have magically time traveled into the future and grabbed an unrelease kernel, or maybe it mugged the Fedora dev's for it. Either way, he needs to get hooked up to a better mirror.

Anyways, back to my point. After hours of getting nowhere, Naveen, a co-worker, walked in and just happen to come up with the answer on the first shot. "Power Management." I knew the drive was ok because all along I could still boot into the old kernel. In grub itself I could read the drive, access any information on it, yet the kernel failed to recognize it after loading from /boot. I tried various attempts at kernel appends, including acpi=off, but no luck. Naveen mentioned that he had wrestled for almost two weeks with a similar problem in Ubuntu on his new quad core motherboard, and that it had to be bios issue.

Sure enough, we rooted through the HP workstation bios for drive controls and turning off "SATA Power Management" did the trick. The kernel booted normally and I was able to fully upgrade without any issues. I'm not sure what was enabled (or disabled) since the 2.6.24 series of kernel, but it had major issues with the SATA controller on this board. If you're having similar issues try finding similar options and selectively turning them off. Linux has always traditionally had issues handling ACPI and other power management controllers, so I'm not surprised.