Gentoo Archives: gentoo-user

From: Rich Freeman <rich0@g.o>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] General weirdness - a tale of woe.
Date: Wed, 27 May 2015 13:21:48
In Reply to: [gentoo-user] General weirdness - a tale of woe. by Peter Humphrey
1 On Wed, May 27, 2015 at 7:59 AM, Peter Humphrey <peter@××××××××××××.uk> wrote:
2 > This is a KDE amd64 system with /usr under / and no initrd.
4 Just to clarify, is /usr on a separate filesystem, or the same as /?
5 I don't think that is your problem in any case, but it might be
6 relevant.
8 > ... bunch of KDE stuff
10 I've had the odd KDE issue along the way, like having extra panels
11 spawning off-screen with notifications showing up in wierd places as a
12 result. That doesn't sound like your specific problem, but assuming a
13 KDE expert doesn't chime in here you might consider pursuing those
14 questions in a KDE forum/list, or maybe even in the Gentoo forums
15 where there is a section for desktop environments. Again, assuming
16 somebody doesn't recognize your problem here.
18 > The last thing is that at reboot the RAID-1 volume manager often fails to
19 > start. It says afterwards that it's running, but all the /dev/vg7/* are absent
20 > (that's where the logical volumes live). The file system root lives on /dev/md5
21 > with metadata < 1.0, while /dev/vg7 has metadata >1.0. The fact that it
22 > happens often but not always suggests a timing problem to me.
24 I've sometimes seen this sort of thing with kernel raid autodetection,
25 especially with metadata <1. I suspect that an initramfs might help
26 you out, assuming the filesystems on that RAID are useful in early
27 boot. However, openrc and the raid init scripts should do a good job
28 of configuring your raid if your mdadm.conf and such is correct, so if
29 you don't need those filesystems until late in boot I don't think an
30 initramfs will make much of a difference, since it would likely use
31 the exact same userspace tools as openrc already does. Make sure your
32 mdadm.conf is set up to search all devices that could contain RAID
33 (drive device names can get re-ordered), and it doesn't hurt to put
34 ARRAY lines in mdadm.conf to give it hints.
36 I do recommend just using an initramfs if you're using RAID for
37 early-boot filesystems. While it is an extra step I find it is much
38 more robust than kernel autodetection (and if something goes wrong you
39 usually get an emergency shell where you can just manually get the
40 RAID up and type exit and watch the system boot). It also lets you
41 use metadata >1 and I find that to be a lot more robust in general.
42 With an initramfs you can basically boot anything you can mount from a
43 booted system, but without one your options are more limited.
45 --
46 Rich


Subject Author
Re: [gentoo-user] General weirdness - a tale of woe. Peter Humphrey <peter@××××××××××××.uk>