Re: [[Patch mdadm] 2/5] Move the files mdmon opens into /dev/ to support handoff after pivotroot

[Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

[-- Attachment #1: Type: text/plain, Size: 2408 bytes --]

On 02/08/2010 09:19 PM, martin f krafft wrote:
> also sprach Neil Brown <neilb-l3A5Bk7waGM@public.gmane.org> [2010.02.09.1038 +1300]:
>> I could probably actually live with "/dev/run" as the permanent
>> home for the mdmon files:  /dev/run/mdmon/*.{sock,pid} It
>> addresses most of the issues I had with the original suggestion
>> (hidden files, non-generic approach) so the "cons" are weaker.
>> And I now understand the "pros" better (races with cleaning
>> /var/run, issues with unmounting /var etc).
> 
> Note that initramfs already carries /dev across the pivot_root, and
> initramfs already uses /dev/.initramfs to carry stuff across.

And the things carried in there should be able to be trivially moved to
a final location.

> I am not sure /dev/run will fly past the Debian Police. On the other
> hand, it would be convenient, since it'll work out-of-the-box, at
> least on Debian systems. I don't really like the idea of a symlink
> in / though. Nor do I really have a better idea.

Persuant to the comments that this should work even if /dev is not
read/write, it really needs to officially be a top level directory (or
else some other mount point that is separate from /dev I think, I guess
it could be in /tmp itself).

>> Anyone second the motion?
> 
> I am all for finding a solution that works, but I don't think it's
> as easy as "the standards are slow, so let's just forge ahead with
> mdadm only and give them something to standardise".
> 
> I wouldn't mind avoiding all the bikeshedding, and maybe it'll just
> work, but having to change things later might possibly be a lot of
> trouble — after all, we don't want to break people's systems then.

I don't think so.  Once it's all set up, any future change should be no
more than a coordinate package update cycle where initscripts, mkinitrd,
dracut, and a few other select packages that use the locations are all
updated simultaneously.

> On the other hand, this is something that is reinitialised on every
> boot, isn't it? If that's the case and there don't seem to be
> complications with a later move, then I say: yeah, let's go ahead.
> 


-- 
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
              GPG KeyID: CFBFF194
	      http://people.redhat.com/dledford

Infiniband specific RPMs available at
	      http://people.redhat.com/dledford/Infiniband


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]