From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: mdadm -A erased the superblock ? Date: Tue, 25 Mar 2008 16:09:24 +1100 Message-ID: <18408.35076.866095.278205@notabene.brown> References: <40829.192.168.1.70.1206129490.squirrel@neil.brown.name> <4510.66972.qm@web32801.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Pradeep on Saturday March 22 Sender: linux-raid-owner@vger.kernel.org To: Pradeep Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Saturday March 22, pradeepjp@yahoo.com wrote: > > > Where there any kernel message (view with 'dmesg') at this time? > > Mar 21 00:27:45 brahma kernel: md: invalid raid superblock magic on sdd > Mar 21 00:27:45 brahma kernel: md: sdd does not have a valid v0.90 superblock, not > importing! > Mar 21 00:27:45 brahma kernel: md: md_import_device returned -22 > So mdadm did try to assemble the array out of /dev/sdd. I wonder why. When it did that, it would have told the kernel to forget about all the partitions on /dev/sdd so they didn't confuse things. This is why /dev/sdd1 etc seem to disappear. > > > What is much more interesting, is that I rebooted the machine, and 'mdadm --examine' > started working again (producing output). > I then retried the 'mdadm -A' command and that went through as well. What do you mean exactly. Did it assemble the array correctly? > I cannot recall if the raid set was originally created on a 32 or a 64 bit O.S. It shouldn't make any difference. > > Is there any other diagnostic I can try ? Not sure... If the array is working now, I don't think there is a need to explore further. If it isn't, maybe strace -o /tmp/strace mdadm -v -A ...... immediately after a reboot might help (Attach "/tmp/strace"). NeilBrown