From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: [Patch] mdadm: move mdadm.map file into /dev/md Date: Tue, 07 Apr 2009 23:04:30 +0200 Message-ID: <87myastbtt.fsf@frosties.localdomain> References: <87tz51dmmu.fsf@frosties.localdomain> <20090407105520.GA29222@maude.comedia.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20090407105520.GA29222@maude.comedia.it> (Luca Berra's message of "Tue, 7 Apr 2009 12:55:21 +0200") Sender: linux-raid-owner@vger.kernel.org To: LinuxRaid RAID List-Id: linux-raid.ids Luca Berra writes: > On Tue, Apr 07, 2009 at 08:05:29AM +0200, Goswin von Brederlow wrote: >>Doug Ledford writes: >> >>> Originally, mdadm used /var/run/mdadm/mdadm.map file to store the >>> temporary mappings of incrementally added devices to device names. >>> Unfortunately, this breaks incremental assembly if used early in the >>> booting process. Specifically, root may still be read only. Since >>> incremental assembly is largely a udev specific feature, and udev >>> needs a writable /dev tmpfs mount even when root is still read only, >>> it's safer to put our mdadm.map file in /dev/md so that we can write >>> to the map file no matter how early in the boot process we are >>> attempting to use incremental assembly. >> >>What about /lib/init/rw? > > What is that?, i never heard of '/lib/init/rw' before > > L. At least under debian that is a tmpfs mounted in /etc/rcS.d/S02mountkernfs.sh for programs that need to write somewhere early in the boot process while potentially / is read-only and tmp and var are still missing. It even runs before /etc/rcS.d/S03udev. MfG Goswin