Re: 2.6.30-rc8 Oops whilst booting

From: Chris Clayton
Date: Mon Jun 08 2009 - 11:17:53 EST

Sorry James, I forgot to ask...

2009/6/8 James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>:
> On Mon, 2009-06-08 at 09:08 +0100, Chris Clayton wrote:
>> Hi Neil,
>> Thanks for the reply.
>> 2009/6/7 NeilBrown <neilb@xxxxxxx>:
>> > On Mon, June 8, 2009 8:31 am, Jaswinder Singh Rajput wrote:
>> >> On Sun, 2009-06-07 at 19:38 +0100, Chris Clayton wrote:
>> >>> 2009/6/7 Jaswinder Singh Ra
>> >>> >> >
>> >
>> > This message says that it found a vfat filesystem on 8:3x (I cannot see
>> > what digit should be 'x').  That is probably sdc1 or sdc2. Maybe even
>> > sdc6 or sdc7.
>> > However the vfat filesystem didn't have /sbin/init.
>> >
>> >>>
>> >
>> > This one says it couldn't find anything at 8,22, which I think
>> > should be sdb6.
>> > It also shows that you have and sdc6, but sdb only goes up to sdb3.
>> >
>> > So it seems that your disk drives have changed name - not a wholely
>> > unexpected event these days.
>> >
>> > We now need answers to questions like:
>> >  - what device do you expect the root filesystem to be on
>> >  - how is the kernel being told this?  Maybe it is hard coded
>> >    into your initrd.  Knowing which distro and what /etc/fstab
>> >    says might help (though it wouldn't help me, I'm just about out
>> >    of my depth at this point)
>> > Maybe if you changed /etc/fstab to mount by uuid instead of hardcoding
>> > e.g. /etc/sdb3, and then run "mkinitramfs" or whatever, it might work.
>> >
>> Yes, I've just been looking at the photographs of the panics again and
>> I've noticed that two of my discs are being detected in the "wrong
>> order". There are three HDDS. The first, /dev/sda, is the master on
>> the first IDE port and contains sda1..sda7. The second, normally
>> /dev/sdb, is the slave on that port and contains sdb1..sdb6. The
>> third, normally /dev/sdc, is attached to the first SATA port and
>> contains sdc1..sdc3. The second photograph I posted shows that sdb and
>> sdc have been reversed. The first partition on the disc that is
>> normally /dev/sdb does indeed have a FAT32 filesystem in the first
>> partition.
>> By the way, I should have said that in between the panics that the two
>> photographs show, I copied contents of /dev/sdc1, which I normally
>> boot from, to /dev/sdb6, so that I minimised the risk to sdc1 in the
>> reboot festival that bisecting would involve. I also, of course,
>> changed the name of the root partition that is passed to the kernel by
>> GRUB and amended /etc/fstab on /dev/sdb6. That's why the partitions
>> shown in the photographs seem inconsistent. Sorry I forgot to mention
>> that - I really shouldn't do these things late at night :-).
> Actually, you can save yourself a lot of pain by mounting by label
> instead ... that way both grub and fstab will find your root disc even
> if it has swapped order.

Would I be right in assuming from this that "out-of-order" detection
is expected behaviour? If so, I'll fix up my system and shut up :-) I
suspect I may not be the only person on the planet who specifies the
root filesystem in this way, though.


>> As I indicate above, when booting the partition I have set up to do
>> this bisecting,  I expect the root filesystem to be on /dev/hdb6. As I
>> also indicate, this information is passed to the kernel through GRUB's
>> /boot/grub/menu.lst. The kernel is configured specifically for my
>> system and the drivers needed to boot the system are built in to the
>> kernel, so I don't use an initrd. IIRC, that's the way Slackware is
>> installed today, except, of course, it's a big fat kernel with all
>> drivers needed to boot any system built in. I could be wrong on that
>> though, it's a while since I installed
> The fact that a slave on the first channel is detected after the SATA
> indicates a problem with async probing.  What are the two drivers for
> these?
> James

No, Sir; there is nothing which has yet been contrived by man, by which
so much happiness is produced as by a good tavern or inn - Doctor Samuel
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