Re: git repo being corrupted?

From: Luciano Rocha <luciano@lsd.di.uminho.pt>
Date: Apr 7, 2008, 11:39 UTC
Message-ID: <20080407113921.GA13667@bit.office.eurotux.com>
In-Reply-To: <47FA03C4.9030104@diamand.org>

On Mon, Apr 07, 2008 at 12:21:40PM +0100, Luke Diamand wrote:

Show 9 quoted lines

> Luciano Rocha wrote:
> 
> >> Linux 2.6.22-3-amd64
> >> File system is XFS
> >> git version 1.5.4.4
> > 
> > You're using XFS. Did you have a power fail in the recent past?
> 
> How did you know?

XFS doesn't order metadata writes with data writes, so if the power fails, it can find an update in the journal but the data wasn't written. Then it fills the file with zeroes to the new size.

I've lost /etc/passwd once with that behaviour...

Also, ext3 doesn't order the metadata and data updates with data=writeback, but the default is data=ordered, which does.

I use xfs, but only when I know I have at least daily backups (or on systems with UPS and with UPS initiated orderly shutdowns).

-- 
lfr
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