constant zfs data corruption

Jeremy Chadwick koitsu at
Mon Oct 20 06:22:11 PDT 2008

On Mon, Oct 20, 2008 at 08:37:40AM -0200, JoaoBR wrote:
> On Friday 17 October 2008 15:39:59 Chuck Swiger wrote:
> > On Oct 17, 2008, at 11:30 AM, JoaoBR wrote:
> > > constantly I find data corruption on ZFS volums, ever from rrdtool,
> > > this
> > > corrupt data happens on SATA disks, never seem on SCSI
> >
> > Presumably your SATA drives are correctly being reported by ZFS as
> > corrupting data, and you should do something like replace cables, the
> > drives themselves, perhaps try downgrading to SATA-150 rather than
> > -300 if you are using the later.  Also consider running a drive
> > diagnostic utility from the mfgr (or smartmontools) and doing an
> > extended self-test or destructive write surface check.
> >
> well, hardware seems to be ok and not older than 6 month, also happens not 
> only on one machine ... smartctl do not report any hw failures on disk
> regarding jumpering the drives to 150 you suspect a driver problem? 

It's not because of a driver problem.  There are known SATA chipsets
which do not properly work with SATA300 (particularly VIA and SiS
chipsets); they claim to support it, but data is occasionally corrupted.
Capping the drive to SATA150 fixes this problem.

There are also known problems with Silicon Image chipsets (on Linux,
Windows, and FreeBSD).

Because you didn't provide your smartctl output, I can't really tell if
the drives are in "good shape" or not.  :-)

Also, do you not think it's a little odd that the only data corruption
occurring for you are related to RRDtool?

| Jeremy Chadwick                                jdc at |
| Parodius Networking              |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |

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