From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wakko Warner Subject: Re: Device state during an incremental assembly Date: Sun, 21 Nov 2010 09:41:59 -0500 Message-ID: <20101121144159.GB29163@animx.eu.org> References: <20101120015225.GA9625@animx.eu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20101121171948.4b793254@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: neilb@suse.de Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids > > I am not on this list, please always CC me. I am now. > > Is there anyway to determine the array state after incrementally adding a > > device? I was hoping to find something in /sys but I was unable to. I was > > trying not to parse the output of mdadm for each invocation. > Yes. > Note: if you don't find that there is enough detail in this answer, it > simply > reflects the level of detail in the question :-) I've been playing with incremental assembly on a test system and wanted to have a way of knowing if the md device was in a state that it could be started. I'm working with a script that will assemble arrays for me and possibly query if an array should be started if it hasn't. For instance. Lets say that I have a 4 disk array (In my case, raid level is really of no importance, but if we must, assume this is raid5). The array was setup as /dev/md0. I run mdadm -I /dev/sda1 Obviously, this is not enough to start the array even in degraded mode. At this point, is there a way to know if the array could be started and usable without parsing the output of mdadm? Next, mdadm -I /dev/sdb1 Still not enough. Next, mdadm -I /dev/sdc1 At this point, I could start the array in degraded. This is what I'd like to beable to query from beneath /sys/block/md0 or some where else. And of course, mdadm -I /dev/sdd1 makes the array fully active. P.S. cantor2.suse.de[195.135.220.15] does pipelining even if pipelining wasn't performed. -- Microsoft has beaten Volkswagen's world record. Volkswagen only created 22 million bugs.