Bug#394193: initramfs-tools: root file system fails to mount when mounting by a label, on top of an md device.

[Chris Andrews]

Im first to admit that it is just a hack. As I do not know 
the innerworkings of udev. I was just repoting the issue,
and my little hack to make things work. 

To rexplain the situation tho. after the initrd does its
mdrun in order to create the various md devices, the raid
devices are created, and working properly, I have the 
appropriate /dev/mdX enteries.  But, after mdrun does the
assembling, /dev/disk/by-label/ and /dev/disk/by-uuid/ are
not populated with symlinks.

And, while, this wouldnt be a problem if i were able to 
simply have my root filesystem pointing to /dev/md0, 
the various sata controllers in my server cause drives
to be probed in different orders , and md devices along
with them.

Ie. my root file system happens to be /dev/md6 right now,
next time it could be /dev/md2. 

So the purpose of running udevtrigger, isnt to force or
manually create /dev/md0 (thats working fine), rather
its to populate /dev/disk/by-label and /dev/disk/by-uuid
with information from assembled md devices. 

I agree this isnt the correct solution, but in practice
it works, without any noticable negative side effects.

--
Chris Andrews
chris-debian at evermeet.org

On Fri, Oct 20, 2006 at 06:08:35PM +0200, Marco d'Itri's all...
> 
> No, this is wrong. DO NOT run udevtrigger for no good reason.
> If you need to trigger a specific event then tickle $DEVPATH/uevent,
> e.g:
> 
> echo add > /sys/block/md0/uevent
> 
> But still, I can't see why this should help: if /sys/block/md0/ exists
> then the MD array has already been activated, so its uevent should have
> been generated too.
> Manually creating /dev/md0 will not activate the device and no uevent
> will be generated, so running udevtrigger cannot help.
>