Gentoo Archives: gentoo-user

From: Daniel Frey <djqfrey@×××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] udev detection weirdness
Date: Thu, 26 May 2016 06:14:45
Message-Id: 57469442.6060701@gmail.com
1 Some time ago (more than a year ago) one of my computers failed to boot
2 after an update (note - not a kernel update. A @world update.) I
3 couldn't figure out why and installed grub2 and used UUIDs as a
4 temporary fix.
5
6 I got a new SSD for that machine today, so I went and moved everything
7 over, then (of course) it wouldn't boot any longer, and I remembered my
8 kludge and spent some time finally figuring out the cause.
9
10 It appears to be udev. Somewhere along in its stupid detection it
11 decides to process USB devices before sata ports, thusly randomly
12 renaming the boot drive to something else in the process.
13
14 It took me forever to figure this out, I eventually had a lightbulb
15 moment and used my phone to record video of it booting, then slowing it
16 down, as when the kernel panics you can't scroll back up to see WTF
17 happened.
18
19 This is an older machine, but I'm not convinced it's the motherboard
20 doing this. I've checked the boot order in the BIOS. I've also tried
21 setting and unsetting "BIOS order determines boot disk" in the kernel
22 config and it made no difference.
23
24 What eventually fixed it was building USB as modules. (Another kludge!)
25
26 I have no custom udev rules, the only rules I could find were in
27 /lib/udev/rules.d:
28
29 10-dm.rules
30 11-dm-lvm.rules
31 13-dm-disk.rules
32 40-gentoo.rules
33 50-udev-default.rules
34 60-block.rules
35 60-cdrom_id.rules
36 60-drm.rules
37 60-evdev.rules
38 60-persistent-alsa.rules
39 60-persistent-input.rules
40 60-persistent-storage-tape.rules
41 60-persistent-storage.rules
42 60-persistent-v4l.rules
43 60-serial.rules
44 64-btrfs.rules
45 69-dm-lvm-metad.rules
46 70-infrared.rules
47 70-mouse.rules
48 70-udev-acl.rules
49 75-net-description.rules
50 75-probe_mtd.rules
51 78-sound-card.rules
52 80-drivers.rules
53 80-net-setup-link.rules
54 80-udisks.rules
55 90-alsa-restore.rules
56 90-network.rules
57 95-dm-notify.rules
58 99-nvidia.rules
59
60 Does anyone have any explanation for this daft behaviour or know where I
61 should look?
62
63 I have multiple machines and it's only this one that has this problem,
64 which happened after a @world update long ago.
65
66 Dan

Replies

Subject Author
[gentoo-user] Re: udev detection weirdness James <wireless@×××××××××××.com>
Re: [gentoo-user] udev detection weirdness Stroller <stroller@××××××××××××××××××.uk>