constant zfs data corruption

[Jeremy Chadwick]

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.

http://en.wikipedia.org/wiki/Serial_ATA#SATA_1.5_Gbit.2Fs_and_SATA_3_Gbit.2Fs

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.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |