From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Hardy Subject: Re: raid1: All my data completely vanished into the void Date: Tue, 27 Dec 2005 20:33:03 -0800 Message-ID: <43B2157F.8030505@h3c.com> References: <200512272340.48483.mlaks@verizon.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200512272340.48483.mlaks@verizon.net> Sender: linux-raid-owner@vger.kernel.org To: Mitchell Laks , linux-raid@vger.kernel.org List-Id: linux-raid.ids Mitchell Laks wrote: > Hi, > > I just set up a new server running stable Debian Sarge, fresh install, > mdadm 1.9.0, linux kernel 2.6.8-2 > and all my (test) data has vanished into the ether. > > What did I do wrong? I don't want this to happen in real life :). [ description of sane-looking md setup snipped ] > Did I screw up everything by not unmounting the devices? What happened? Failure to unmount the devices should have resulted in possibly last writes but a journalling filesystem would have kept things consistent. Failure to nicely stop the arrays also could have possibly degraged the arrays if they were being written to as the machine went down, but they should be there. In short: it *definitely* should *not* have come back with what you saw. I have no clue why this happened, all I can say is that I use md on around 10 business critical production machines in exactly the way you describe, and I have not seen this (though I've seen the failure modes I described!). Are you positively sure that nothing else weird could have been going on? Some layer that remaps drive names? funky hardware? write caching capable of holding 3GB before writing out? Write caching of some sort is actually my best guess. If there's no extra data to explain this, I'm at a loss. Anyone else? -Mike