Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 20 Oct 2008 13:57:24 -0400
From:      "Zaphod Beeblebrox" <zbeeble@gmail.com>
To:        "Jeremy Chadwick" <koitsu@freebsd.org>
Cc:        freebsd-stable@freebsd.org, JoaoBR <joao@matik.com.br>
Subject:   Re: constant zfs data corruption
Message-ID:  <5f67a8c40810201057x7bc9353dpebcea7c5abe7d30@mail.gmail.com>
In-Reply-To: <20081020173221.GA8889@icarus.home.lan>
References:  <200810171530.45570.joao@matik.com.br> <20081020164831.GA8016@icarus.home.lan> <45836B9A-CB6E-4B95-911E-0023230B8F82@mac.com> <200810201518.01678.joao@matik.com.br> <20081020173221.GA8889@icarus.home.lan>

next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Oct 20, 2008 at 1:32 PM, Jeremy Chadwick <koitsu@freebsd.org> wrote:

> On Mon, Oct 20, 2008 at 03:18:01PM -0200, JoaoBR wrote:
> > On Monday 20 October 2008 15:03:14 Chuck Swiger wrote:
> > > On Oct 20, 2008, at 9:48 AM, Jeremy Chadwick wrote:
> > > > Hm... I thought we determined earlier in this thread that the OP is
> > > > not
> > > > getting the benefits of ZFS checksums because he's not using raidz
> > > > (only
> > > > a single disk with a single pool)?
> > >
> > > He's not getting working filesystem redundancy with the existing
> > > config and is vulnerable to losing data from a single drive failure,
> > > agreed.  But the ZFS checksum mechanism should still be working to
> > > detect data corruption, even though ZFS cannot recover the corrupted
> > > data the way it otherwise would if redundancy was available.
> > >
> >
> > all right and understood but shouldn't something as fsck should correct
> the
> > error?
>
> No.  You're using ZFS, not UFS.  fsck will not work.
>
> In the case of underlying data corruption on ZFS, there is no way to fix
> it unless you have mirroring or raidz in use.
>

Assuming the whole disk isn't bad and without knowing where (how far away)
ZFS puts things when you do this, setting "copies=2" or "copies=3" on a
non-redundant disk/pool/filesystem will allow ZFS to recover data if one of
the copies is still good.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?5f67a8c40810201057x7bc9353dpebcea7c5abe7d30>