Re: [gentoo-user] gentoo-sources-2.6.35-r12 causes kernel panic

[Mark Knecht]

On Sat, Nov 27, 2010 at 9:17 AM, Mick <michaelkintzios@×××××.com> wrote:
> On Saturday 27 November 2010 15:17:43 Mark Knecht wrote:
>> On Sat, Nov 27, 2010 at 6:59 AM, Mick <michaelkintzios@×××××.com> wrote:
>> > I haven't had much luck with the 2.6.35 version of kernels - they have
>> > cause panics on two different x86 boxen.
>> >
>> > Now that 2.6.35 has gone stable so I tried it again and I'm getting a
>> > kernel panic complaining about VFS unable to mount root fs:
>> > ==================================
>> > VFS:  Cannot open root device "sda3" or unknown-block(0,0)
>> > Please append a correct "root=" boot option; here are the available
>> > partitions: Kernel panic - not syncing: VFS: Unable to mount root fs on
>> > unknown-block(0,0) Pid: 1, comm: swapper Not tainted 2.6.35-gentoo-r12
>> > #2
>> > Call Trace:
>> >  [<c14b3530>] ? panic+0x5f/0xc6
>> >  [<c1693c68>] ? mount_block_root+0x1c2/0x245
>> >  [<c1002930>] ? do_signal+0x766/0x7f2
>> >  [<c1693d31>] ? mount_root+0x46/0x5a
>> >  [<c1693e8b>] ? prepare_namespace+0x146/0x182
>> >  [<c1093203>] ? sys_access+0x1f/0x23
>> >  [<c16933f1>] ? kernel_init+0x1a9/0x1b7
>> >  [<c1693248>] ? kernel_init+0x0/0x1b7
>> >  [<c10030b6>] ? kernel_thread_helper+0x6/0x10
>> > panic occurred, switching back to text console
>> > ==================================
>>
>> <SNIP>
>>
>> > Am I missing something obvious to make the 2.6.35 series work with my
>> > boxen?
>
>>    OK, there's so many possibilities for what causes this. Basic
>> confusion ensues...
>>
>> 1) When booting, if you look carefully, is the initial kernel seeing
>> _any_ disks? Sometimes they fly bye and are hard to catch. If it is
>> then is it showing sda3?
>
> The moment the monitor comes on it's already crashed - the first line under
> the penguins shows:
>
> Initializing USB Mass Storage driver...
>
> so I assume that any probing of drives has already happened.
>
>> 2) What sort of file system did you put on sda3? I assume this is
>> built into the kernel if this is an upgrade?
>
> reiserfs built into the kernel and unchanged for the last umpteen kernel
> series.
>
>> 3) Post the appropriate part of grub.conf to show how you are booting.
>
> title=Gentoo Linux 2.6.35-r12
> root (hd0,5)
> kernel /kernel-2.6.35-gentoo-r12 root=/dev/sda3
>
> The 2.6.34-r12 uses the same stanza except for *.35 being replaced with *.34
>
>> 4) Post fstab
>
> /dev/sda6     /boot      ext2            noauto,noatime          1 1
> /dev/sda3     /          reiserfs        noatime                 0 1
> /dev/sda2     none       swap            sw                      0 0
> [snip]
>
> I'll now build the kernel on the second x86 box and see what happens there.
> --
> Regards,
> Mick
>

Yeah, all makes sense what you've done and I can only offer one more
thing for you to look at.

I skipped from 2.6.33 to 2.6.36 so I cannot say anything specific
about the *.35 series, but one thing I've suffered with on my 2.6.36
build is that if I have a specific USB hub hooked up my machine won't
complete a boot. I have to disconnect this USB hub prior to boot and
then hook it back up after the boot completes.

I've not had time to look for the cause so I only hook it up to use
it. After boot there are no other problems I've seen.

I was assuming that maybe there's some difference in the USB stuff
that I hadn't discovered yet, and since you see a crash at a USB step
possibly it's similar and I never saw it at *.35 because I never used
that series?

Good luck and I wish I could be of more help.

Cheers,
Mark