[gentoo-user] Re: udev detection weirdness

[Hans]

On 26/05/16 23:39, James wrote:
> Daniel Frey <djqfrey <at> gmail.com> writes:
>
>
>> It appears to be udev. Somewhere along in its stupid detection it
>> decides to process USB devices before sata ports, thusly randomly
>> renaming the boot drive to something else in the process.
>
>> It took me forever to figure this out, I eventually had a lightbulb
>> moment and used my phone to record video of it booting, then slowing it
>> down, as when the kernel panics you can't scroll back up to see WTF
>> happened.
>
> Kernel crash dumps might help [1]
>
>
>
>> This is an older machine, but I'm not convinced it's the motherboard
>> doing this. I've checked the boot order in the BIOS. I've also tried
>> setting and unsetting "BIOS order determines boot disk" in the kernel
>> config and it made no difference.
>
> You might want to 'emerge -1 sys-apps/hwids'
>
>
>> What eventually fixed it was building USB as modules. (Another kludge!)
>
> There are numerous 'usb sniffers' that  capture data. Some clue
> might be found using a usb sniffer.
>
>
>
>> I have no custom udev rules, the only rules I could find were in
>> /lib/udev/rules.d:
>
> I use sys-fs/eudev.   ymmv.
>
>
>> Does anyone have any explanation for this daft behaviour or know where I
>> should look?
>> I have multiple machines and it's only this one that has this problem,
>> which happened after a  <at> world update long ago.
>
> If you have a similar setup on similar hardware, then 'diff' the  (dmesg)
> boot log files for any differences and analyze.
>
>
> hth,
> James
>
> [1] https://wiki.gentoo.org/wiki/Kernel_Crash_Dumps
>
>
>
I had similar problems. Fixed them permanently by using disk labels on 
all partitions on all computers.