From mboxrd@z Thu Jan 1 00:00:00 1970 From: cwillu Subject: Re: Error mounting multi-device fs after restart Date: Tue, 8 Feb 2011 16:04:58 -0600 Message-ID: References: <201102082251.38094.hka@qbs.com.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Hubert Kario , linux-btrfs@vger.kernel.org To: Diwaker Gupta Return-path: In-Reply-To: List-ID: On Tue, Feb 8, 2011 at 3:59 PM, Diwaker Gupta wrote: >> Define *indefinitely*. > > Meaning the messages continued for as long as the system was under observation. > >> Are the drives not working? > > I believe they are. Working in the sense that I can read off data > using 'dd', I can inspect partition tables etc. > >> If the drives are working, have you tried waiting 2-3 days, possibly longer? >> 10TB is a *lot* of data > > The system was running overnight when I first hit the problem. On > subsequent reboots, I've only waited less than half an hour. Usually > the mount is instantaneous, so I wasn't sure if waiting would help at > all. The error messages did not indicate that the system could recover > at that stage. If there's even a slight chance that the fs would > eventually mount, I'm happy to let it run for a day or two. Note that > if I mount using the 'degraded' option, the mount succeeds but > subsequent attempts to read the data fail. Huh. How do those attempts fail? Try mounting ro, or degraded,ro, and reading the data off. That worked for me recently on a broken btrfs raid10 (and didn't on another one, so your mileage may vary). There's also the perpetually imminent fsck development which might save the day.