On Wed, Dec 22, 2010 at 13:00, Phong Nguyen wrote: > Have you tried determining what's in mdadm.conf in the initrd file? It > might be getting some incorrect assembly instructions for md0.
This may well be the issue. Other than /etc/modprobe.conf (which is obvious from the mkinitrd man page) and /etc/mdadm.conf, what does the initrd file look at (or where can I find out)? > On 22 Dec 2010, at 1203, Pann McCuaig wrote: > > > Greetings SL fans, > > > > Sorry for the length of this post, but I'm hoping someone can come to my > > rescue and want to provide sufficient context. > > > > Recently I had a hard drive failure on a Sun X4600 box running SL4.8. > > The box has four drives; the drive that failed was /boot (only). The > > other three drives make up /dev/md0. > > > > The /boot drive was not backed up (headsmack!). > > > > I have created a rescue USB stick based on the System Rescue CD, which > > boots via grub. I can boot the System Rescue CD successfully, and it > > sees /dev/md0, which I can then mount and read from and write to. > > > > I have attempted to create a kernel and initrd image to add to the USB > > stick that will boot the box as if the kernel and initrd image were on > > the failed (and now removed) boot drive. > > > > I built the kernel and initrd image on a box similar to the box with the > > failed hard drive. I replaced /etc/modprobe.conf with the file from the > > target server, and then did 'yum install kernel-largesmp'. I copied all > > the resulting kernel-related files from /boot to the USB stick, as well > > as the appropriate directory from /lib/modules. > > > > I then restored the helper box to its original state. > > > > I booted the System Rescue CD on the target system and copied the > > /lib/modules directory into place on /dev/md0. I fixed up grub/menu.lst > > to have a stanza to boot the newly created SL4 kernel. I rebooted the > > box, and everything seemed to be going swimmingly, until . . . > > > > . . . the booted kernel seems unable to build /dev/md0 and the boot > > process fails. > > > > In the original configuration, the boot drive was /dev/sda, and the > > drives making up the soft RAID partition were /dev/sdb, dev/sdc, and > > /dev/sdd. > > > > The System Rescue CD detects the USB stick as /dev/sda and the three SAS > > drives as sdb, sdc, and sdd. All is well. > > > > It's not clear to me what is going awry with the SL kernel, but as > > the boot verbiage scrolls by, I see /dev/sdc referenced twice, and no > > reference to /dev/sdd. When the kernel attempts to assemble /dev/md0, it > > uses /dev/sda, /dev/sdb, and /dev/sdc and this fails and /dev/md0 cannot > > be mounted and the kernel panics. > > > > Help, please. Suggestions? Thanks. > > > > BTW, I've put both SL4.8 Disc One, and the SL4.8 Live CD on a bootable > > USB stick; both boot successfully, but I was unable to find a way to > > make either one recognize /dev/md0, much less "rescue" me. > > > > Cheers, > > Pann -- Pann McCuaig <[email protected]> 212-854-8689 Systems Coordinator, Economics Department, Columbia University Department Computing Resources: http://www.columbia.edu/cu/economics/computing/
