From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Denis Bueno" Subject: Re: Recovering from repository corruption Date: Tue, 10 Jun 2008 18:09:20 -0400 Message-ID: <6dbd4d000806101509l516cf467me06fadee6ead0964@mail.gmail.com> References: <6dbd4d000806101026m458513ecqa8141f509bad7602@mail.gmail.com> <6dbd4d000806101238v2bb975abqd39916e45d4bf866@mail.gmail.com> <200806102159.02875.jnareb@gmail.com> <6dbd4d000806101303j4b2032ajc6e004e0a82e4db5@mail.gmail.com> <6dbd4d000806101328k1fc913f2ia55c3e44273ec5ad@mail.gmail.com> <6dbd4d000806101422j39709906x1b4b03b82b504e62@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Git Mailing List" To: "Linus Torvalds" X-From: git-owner@vger.kernel.org Wed Jun 11 00:11:29 2008 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1K6C3m-00036y-NN for gcvg-git-2@gmane.org; Wed, 11 Jun 2008 00:11:23 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759952AbYFJWJZ (ORCPT ); Tue, 10 Jun 2008 18:09:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759481AbYFJWJY (ORCPT ); Tue, 10 Jun 2008 18:09:24 -0400 Received: from fg-out-1718.google.com ([72.14.220.152]:56963 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759551AbYFJWJW (ORCPT ); Tue, 10 Jun 2008 18:09:22 -0400 Received: by fg-out-1718.google.com with SMTP id 19so1930377fgg.17 for ; Tue, 10 Jun 2008 15:09:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=89IaYpE6830CawsJCCCFyW21eSbrMV5x8uk3dLMmkwY=; b=nm3iSfpZYD04Ldb0Zm3SyM1ihFYXBsovPquQw5gof2REvcmO9GlRvAMgTwjhd5FYPe AkKqj5LvrJ5Pjwj6Mhk6I7xI8pCw8Ky9zKMfRdhxGRMd8aQnZwN5d8TtdIDRPmnpThcq M6dcUTM+xJ8HTGm8iZ+MYi8TfSzypcfdO1SXI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=ZnIZLwYV4P9COvCoAhkVm2tJcvuBODKjVK92vFEslWx5K2ZMpjb9QPTCcgGkbiic9X /HZ6xVisq9utSmObwvlQODhrlb+DI46zoF/KIeB+RQTIGMDG701RaGwZ3EiF2Cq1hiF/ qy34FZYiyFqawjcoYIZ/UV3gJfd7Jt56cES1U= Received: by 10.86.72.3 with SMTP id u3mr1260064fga.35.1213135760923; Tue, 10 Jun 2008 15:09:20 -0700 (PDT) Received: by 10.86.59.7 with HTTP; Tue, 10 Jun 2008 15:09:20 -0700 (PDT) In-Reply-To: Content-Disposition: inline Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, Jun 10, 2008 at 17:48, Linus Torvalds wrote: > > > On Tue, 10 Jun 2008, Denis Bueno wrote: >> > >> > then *if* you have the files >> > >> > .git/objects/32/0bd6e82267b71dd2ca7043ea3f61dbbca16109 >> > .git/objects/4d/0be2816d5eea5ae2b40990235e2225c1715927 >> > >> > then those two files are interesting in themselves (most likely they are >> > not there at all, or are zero-sized, but if you have them, please post >> > them). >> >> They are attached, and they are not zero-sized. > > Very interesting. > > Both of them look fairly sane as objects (ie random - it's supposed to eb > zlib-compressed), but both of them have the first 512 bytes *identically* > corrupted: > > 0000000 6564 626e 6575 406e 6f64 6f72 6874 2e79 > d e n b u e n @ d o r o t h y . > 0000020 6f6c 6163 2e6c 3634 0033 0000 0000 0000 > l o c a l . 4 6 3 \0 \0 \0 \0 \0 \0 \0 > 0000040 0000 0000 0000 0000 0000 0000 0000 0000 > \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 > * > > ie it's an all-zero block, except for that email-looking thing at the > head. Right --- that's my username and computer's hostname... for some reason. [You are not expected to understand this. My computer's name mysteriously changed. It should not be "dorothy.local" but it is. I will have to find out why....] > One thign that strikes me is that you seem to be really prone to this > problem, since it happened to you a year ago too. I cannot swear to this, > but I literally suspect your last case (July-2007) was the previous time > we had a corruption issue. Why does it seem to happen to you, but not > others? It is the same computer on which the problem occurred last time. It's an OS X 10.4 macbook pro. I haven't noticed corruption in other places, but it's fair to assume it's occurring. I'll have to boot off my install disk and fsck the drive.... > Do you have some odd filesystem in play? Was the current corruption in a > similar environment as the old one? IOW, I'm trying to find a pattern > here, to see if there might be something we can do about it.. I can't remember if the old one happened after a panic or not, but I'd bet it did. The filesystem is HFS+, as indeed most OS X 10.4 installations are. Maybe the HD has been going south? However, that doesn't seem likely, since when I got the computer it was new, and that was around Jun 2007. > But it *sounds* like the objects you lost were literally old ones, no? Ie > the lost stuff wasn't something you had committed in the last five minutes > or so? If so, then you really do seem to have a filesystem that corrupts > *old* files when it crashes. That's fairly scary. What FS is it? No, in fact I had just committed those changes not 10 minutes before the panic. Last time they were also fresh changes, although perhaps older than 10 minutes. I can't remember. -- Denis