This is still a mystery. However, I re-ordered the SATA leads so that the root drive was on SATA 0. It now boots with all drives working. Is this black magic? I didn't change the IDE.
Interestingly, the noise that I thought was a beetle dying in the back of a cupboard turned out to be a noise in the power supply of this machine! The noise started yesterday, not long before I first ran into this problem. Is this a co-incidence? I'm now pretty sure the power supply is on the way out. I've been regularly re-booting this configuration for about a year without it every causing problems previously. > [email protected] wrote: >>>>>>>> "david" == david <[email protected]> writes: >>>>>>>> >>>>> On 26/01/10 23:25, [email protected] wrote: >>>>> >>>>>> After doing a routine reboot I get grub error 15 on Ubuntu 8.10 >>>>>> >>>>> Does this error occur before or after the GRUB menu appears? >>>>> >>>>> i.e. do you get presented with a menu to select which kernel at >>>>> all, or does it bomb out before it gets to that stage? >>>>> >>>>> >>>>>> When I enter the BIOS I am only getting one option for booting >>>>>> into a hard-drive, although I recollect that previously I had to >>>>>> select which hard drive. >>>>>> >>>>>> The BIOS does recognise all three hard drives as being present. I >>>>>> am able to mount the bootable drive from a live CD and the data >>>>>> appears to be OK. >>>>>> >>>>>> Any suggestions what has gone amiss? >>>>>> >>>>> It may well be that the GRUB MBR is simply looking at the wrong >>>>> drive for the menu.lst file. In which case, re-running grub-install >>>>> would be my first suggestion as a fix. >>>>> >>>>> >>> david> It bombs before the kernel list. I've tried running: >>> >>> david> #grub-install /dev/sdc Could not find device for /boot: Not >>> david> found or not a block device. >>> >>> Hmmm. This sounds as if the mapping from BIOS to Linux drives is >>> broken. >>> >>> Try grub-install with the --recheck option. >>> >> >> >> >> The plot thickens ..... >> >> # grub-install --recheck /dev/sdc3 >> Could not find device for /boot: Not found or not a block device >> >> >> I unplugged all but the root drive and it boots perfectly. Progressively >> replugging all the drives seems to have random results. There is one IDE >> drive and three SATA, one of which is the rood drive and another one is >> in >> a caddy. I have had as many as two of the four extra drives running but >> can't get them all to go at once. >> >> I'm beginning to think it's a BIOS/motherboard problem. >> >> I've just rebooted again with only the boot drive plugged in. >> >> > I'll wager you have the grub MBR sitting on one of your other drives > and the bios (as most do) randomly changes the boot order when you add > new drives, so having that one in a caddy will mess with things. > when it decides to boot off the one with the other grub you get an error. > > you can zero it if you want and see if that helps > backup first > dd if=/dev/hda of=/mbrbackup.bin bs=512 count=1 > > then zero > dd if=/dev/zero of=/dev/hda bs=446 count=1 > > note the 446 bytes, if you do 512 it'll wipe the partition table (which > is a bad thing) > > if your lucky that'll be enough that the bios will skip those when it > comes to boot time. > > make sure your fstab is all done by uuid not path because that will > probably change as you add and remove drives or the phase of the moon > changes. > > > > > -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
