From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: mdadm RAID5 Grow Date: Tue, 28 Nov 2006 18:56:03 -0500 Message-ID: <456CCC93.1080201@tmr.com> References: <6652499.post@talk.nabble.com> <17700.35743.152233.689956@cse.unsw.edu.au> <4524FD70.6070609@mickg.net> <17701.504.201046.256698@cse.unsw.edu.au> <45257D7B.90401@mickg.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <45257D7B.90401@mickg.net> Sender: linux-raid-owner@vger.kernel.org To: mickg Cc: Neil Brown , linux-raid@vger.kernel.org List-Id: linux-raid.ids mickg wrote: > Neil Brown wrote: >> On Thursday October 5, mickg@mickg.net wrote: >>> Neil Brown wrote: >>>> On Wednesday October 4, mickg@mickg.net wrote: >>>>> I have been trying to run: mdadm --grow /dev/md0 --raid-devices=6 >>>>> --backup-file /backup_raid_grow >>>>> I get: >>>>> mdadm: Need to backup 1280K of critical section.. >>>>> mdadm: /dev/md0: Cannot get array details from sysfs >>>> It shouldn't do that.... Can you strace -o /tmp/trace -s 300 >>>> mdadm --grow ..... >> ... >>> open("/sys/block/md0/md/component_size", O_RDONLY) = -1 ENOENT (No >>> such file or directory) >> >> So it couldn't open .../component_size. That was added prior to the >> release of 2.6.16, and you are running 2.6.17.13 so the kernel >> certainly supports it. Most likely explanation is that /sys isn't >> mounted. >> Do you have a "/sys"? >> Is it mounted? >> Can you "ls -l /sys/block/md0/md" ?? >> >> Maybe you need to >> mkdir /sys >> mount -t sysfs sysfs /sys >> >> and try again. >> > Worked like a charm! > > Thank you! > > There is a > sysfs /sys sysfs noauto 0 0 > line in /etc/fstab > I am assuming noauto is the culprit? > > Should it be made to automount ? > > mickg I will belatedly add that experience shows that /proc and /sys are optional (and can in theory be mounted other places), in practice a lot of software depends on them being present and in the usual place. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979