Re: [gentoo-user] General weirdness - a tale of woe.

[Peter Humphrey]

On Wednesday 27 May 2015 09:21:37 Rich Freeman wrote:
> On Wed, May 27, 2015 at 7:59 AM, Peter Humphrey <peter@××××××××××××.uk>
wrote:
> > This is a KDE amd64 system with /usr under / and no initrd.
>
> Just to clarify, is /usr on a separate filesystem, or the same as /?
> I don't think that is your problem in any case, but it might be
> relevant.

I didn't realise I wasn't clear, sorry. It might have been better if I'd said 
usr/ is under /. Anyway, it's not a separate partition.

> > ... bunch of KDE stuff
>
> I've had the odd KDE issue along the way, like having extra panels
> spawning off-screen with notifications showing up in wierd places as a
> result.  That doesn't sound like your specific problem, but assuming a
> KDE expert doesn't chime in here you might consider pursuing those
> questions in a KDE forum/list, or maybe even in the Gentoo forums
> where there is a section for desktop environments.  Again, assuming
> somebody doesn't recognize your problem here.

Since writing, I've found that my fonts have all changed as well. It's almost 
as though something were cruising my home directories and flipping bits. And 
KMail insists on using American English in the composer, despite my telling it 
UK. That may not be new though.

I'm signed up to the KDE-Linux list already but I see hardly any traffic, and I 
suspect dark things about what happens to posts of mine on it.

> > The last thing is that at reboot the RAID-1 volume manager often fails to
> > start. It says afterwards that it's running, but all the /dev/vg7/* are
> > absent (that's where the logical volumes live). The file system root
> > lives on /dev/md5 with metadata < 1.0, while /dev/vg7 has metadata >1.0.
> > The fact that it happens often but not always suggests a timing problem
> > to me.
>
> I've sometimes seen this sort of thing with kernel raid autodetection,
> especially with metadata <1.

More clarity needed on my part. The file-system root is /dev/md5 which has 
metadata < 1.0. It's found reliably by kernel autodetection. Subsidiary 
partitions are in /dev/md7 which has metadata > 1.0 and lvm2 volumes. Here's a 
bit of fstab:

/dev/vg7/portage    /usr/portage            ext4  relatime,discard  1 3
/dev/vg7/packages   /usr/portage/packages   ext4  relatime,discard  1 2
/dev/vg7/distfiles  /usr/portage/distfiles  ext4  relatime,discard  1 2
/dev/vg7/local      /usr/local              ext4  relatime,discard  1 2

It's the detection of md7 that often fails; I've had no trouble with md5.

Several other directories are in lvm2 volumes in /dev/vg7, but nothing that's 
part of system.

> I suspect that an initramfs might help
> you out, assuming the filesystems on that RAID are useful in early
> boot.  However, openrc and the raid init scripts should do a good job
> of configuring your raid if your mdadm.conf and such is correct, so if
> you don't need those filesystems until late in boot I don't think an
> initramfs will make much of a difference, since it would likely use
> the exact same userspace tools as openrc already does.  Make sure your
> mdadm.conf is set up to search all devices that could contain RAID
> (drive device names can get re-ordered), and it doesn't hurt to put
> ARRAY lines in mdadm.conf to give it hints.

Like this?
ARRAY /dev/md1 devices=/dev/sda1,/dev/sdb1
ARRAY /dev/md5 devices=/dev/sda5,/dev/sdb5
ARRAY /dev/md7 devices=/dev/sda7,/dev/sdb7

> I do recommend just using an initramfs if you're using RAID for
> early-boot filesystems.  While it is an extra step I find it is much
> more robust than kernel autodetection (and if something goes wrong you
> usually get an emergency shell where you can just manually get the
> RAID up and type exit and watch the system boot).  It also lets you
> use metadata >1 and I find that to be a lot more robust in general.
> With an initramfs you can basically boot anything you can mount from a
> booted system, but without one your options are more limited.

Well, that's an interesting idea - thanks. I'll give it some thought.

I've just switched on a few more sensors in gkrellm, and I see Vcor2 at 3.00 
and +3.3v at 3.34. Is it worth fiddling with those and related settings in the 
BIOS? I've always hesitated to do that, preferring to let it sort itself out.

-- 
Rgds
Peter