From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Myers Subject: Re: Need urgent help in fixing raid5 array Date: Mon, 5 Jan 2009 18:46:04 -0800 (PST) Message-ID: <100979.40008.qm@web30803.mail.mud.yahoo.com> References: <451872.61166.qm@web30802.mail.mud.yahoo.com> <467705.96388.qm@web30807.mail.mud.yahoo.com> <344038.60917.qm@web30808.mail.mud.yahoo.com> <18786.34165.639790.37753@notabene.brown> <546794.45786.qm@web30802.mail.mud.yahoo.com> <879ae2ec7c5524fd9fa9841245772ab6.squirrel@neil.brown.name> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: Justin Piszcz , linux-raid@vger.kernel.org, john lists List-Id: linux-raid.ids BTW, don't I need to use the --assume-clean option in the create operation to have this work right? Thanks, Mike ----- Original Message ---- From: NeilBrown To: Mike Myers Cc: Justin Piszcz ; linux-raid@vger.kernel.org; john lists Sent: Monday, January 5, 2009 2:53:43 PM Subject: Re: Need urgent help in fixing raid5 array On Tue, January 6, 2009 9:22 am, Mike Myers wrote: > Thanks! I see what you are doing here. So since none of these commands > actually change the underlying data, if I get the order right. the array > will come up and the LVM superblock will be visible, and then I can try > and bring the filesystem online? If I get the order wrong, I can just try > it again with another combination. Do I have that right? Exactly, yes. > > I should probably print out all the existing metadata and save it since > the data will be wiped out by the create. Certainly a good idea. > > How could the drives get the bad metadata on them> I've played with > software raid for about 4 years and have seen seen something this strange. I really cannot think how they could get the particular bad metadata that they did. "mdadm --add" will change the metadata, but only to make the device appear to be a spare, which isn't the case here. "mdadm --assemble --force" can re-write the metadata, but again I cannot imagine it making the particular change that has been made. Maybe there is a bug in there somewhere. NeilBrown