From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: [[Patch mdadm] 2/5] Move the files mdmon opens into /dev/ to support handoff after pivotroot Date: Wed, 10 Feb 2010 12:33:21 +1100 Message-ID: <20100210123321.324e5de6@notabene.brown> References: <1263242294-5353-3-git-send-email-dledford@redhat.com> <20100119110930.107ca42e@notabene> <4B55F138.7060008@redhat.com> <20100204174009.6072ec07@notabene.brown> <4B6B15B3.8030205@redhat.com> <4B6DAC06.6060909@redhat.com> <4B702EA5.3030103@redhat.com> <20100209083838.6568cac0@notabene.brown> <20100209021949.GB11780@lapse.rw.madduck.net> <4B71C6CA.3010407@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: initramfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Mr. James W. Laferriere" Cc: Doug Ledford , Dan Williams , linux-raid maillist , initramfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Marek , Hans de Goede , Bill Nottingham List-Id: linux-raid.ids On Tue, 9 Feb 2010 15:58:52 -0900 (AKST) "Mr. James W. Laferriere" wrote: > Hello Doug , > > On Tue, 9 Feb 2010, Doug Ledford wrote: > > On 02/08/2010 09:19 PM, martin f krafft wrote: > ...snip... > >> 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. > > The key words in the above are: 'select packages' & 'simultaneously' . > How is the community of linux distributors going to accomplish this ? > Heck some of the distributors don't even use the same names for packages > that do exactly the same thing . > > The Simultainity is going to hurt alot more than is mentioned here . Simultaneity only needs to be within one host, not across all distros. I don't think it should be that hard to manage. > > But that said , the idea of a /'name' area for this is imo a very good > thing . Rather hiding it below others . Thanks. One idea that has occurred to me is that maybe /sys is the right place to put this stuff!!! If only sysfs directories could be writeable, I could write the pid file in /sys/class/block/md0/md/mdmon.pid and create a socket with a similar name. I could of course get the md module to create a file called "mdmon.pid" and allow it to be read and written much like a normal file. But I don't think I want to do that - and I couldn't use that solution for the socket in any case. Not a short-term solution, but something to keep in mind longer-term maybe... NeilBrown