From: Simone Ferretti <simone@galliera.it>
To: linux-btrfs@vger.kernel.org
Subject: Re: mount problem
Date: Wed, 24 Sep 2014 16:28:35 +0200 [thread overview]
Message-ID: <20140924142835.GA18272@galliera.it> (raw)
In-Reply-To: <pan$b29db$c1fc8f39$f1e6e06c$d6b3042c@cox.net>
Wed, Sep 24, 2014 at 01:23:32PM +0000, Duncan wrote:
> Simone Ferretti posted on Tue, 23 Sep 2014 14:06:41 +0200 as excerpted:
>
> > we're testing BTRFS on our Debian server. After a lot of operations
> > simulating a RAID1 failure, every time I mount my BTRFS RAID1 volume the
> > kernel logs these messages:
> >
> > [73894.436173] BTRFS: bdev /dev/etherd/e30.20 errs:
> > wr 33036, rd 0, flush 0, corrupt 2806, gen 0
> > [73894.436181] BTRFS: bdev /dev/etherd/e60.28 errs:
> > wr 244165, rd 0, flush 0, corrupt 1, gen 4
> >
> > Everything seems to work nice but I'm courious to know what these
> > messages mean (in particular what do "gen" and "corrupt" mean?).
>
> Gen=generation. The generation or transaction-ID (different names for
> the exact same thing) is a monotonically increasing integer that gets
> updated every time a tree update reaches all the way to the superblock.
> In the error context, it means the superblock had one generation number
> but N other blocks had a different (presumably older) generation number.
>
> Corrupt is simply the number of blocks where the calculated checksum
> didn't match the recorded checksum, thus indicating an error.
>
> See btrfs device stats -z to reset the numbers to zero (after printing
> them one last time).
Thank you much for your quick and illuminating answer.
I'm wondering if you (or anyone else of course) know if there is btrfs
documentation/papers/anything (besides wiki I did not find anything),
in which it's possible to learn this kind of informations?
--
Bye,
Simone
next prev parent reply other threads:[~2014-09-24 14:28 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-23 12:06 mount problem Simone Ferretti
2014-09-24 13:23 ` Duncan
2014-09-24 14:28 ` Simone Ferretti [this message]
2014-09-25 5:34 ` Duncan
-- strict thread matches above, loose matches on Subject: below --
2011-01-12 0:25 Leonidas Spyropoulos
2011-01-12 0:48 ` Tsutomu Itoh
2011-01-12 0:58 ` Leonidas Spyropoulos
2011-01-12 1:38 ` Leonidas Spyropoulos
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