errors from external USB disk

[Polytropon]

On Thu, 27 Feb 2014 12:59:34 +0100, Matthias Apitz wrote:
> El día Wednesday, February 26, 2014 a las 02:55:27PM +0100, Polytropon escribió:
> 
> > On Wed, 26 Feb 2014 13:17:14 +0100, Matthias Apitz wrote:
> > > Sometimes, after the dump finished, a re-read of the file to get the MD5
> > > checksum results in errors and I was highly concerned about the integrity
> > > of my dumps on this device.
> > 
> > What error? Can you post the error message and the command
> > which caused it?
> 
> While copying big files from the failing disk to another with 'cp -Rp'
> I saw:
> 
> Feb 23 18:48:07 La-Habana kernel: (da0:umass-sim0:0:0:0): READ(10). CDB:
> 28 00 01 cf d9 cf 00 00 0e 00 
> Feb 23 18:48:07 La-Habana kernel: (da0:umass-sim0:0:0:0): CAM status:
> CCB request completed with an error
> Feb 23 18:48:07 La-Habana kernel: (da0:umass-sim0:0:0:0): Retrying command

So it's definitely a reading error here.



> > > I bought another 2.5 TB disk and was able to copy all the files (around
> > > 1TB) over, i.e. the device could now be owerwritte while testing.
> > > 
> > > What is the best way to run a test on the disk? I'm thinking in
> > > something like reading/writing the block in place for many days
> > > (it's around 1.5 TB). Any ideas?
> > 
> > You can start by looking at the S.M.A.R.T. data (sysutils/smartmontools
> > and sysutils/smartcontrol), see "man smartctl" for "smartctl -a".
> > This should help you to identify possible hardware errors.
> 
> I dis this already, but it does not show much:
> [...] 
> Error Counter logging not supported
> 
> Device does not support Self Test logging

Sorry, I forgot to mention: SMART usually does not work over USB.
Do you have the chance to attach the disk, probably a SATA drive,
to a "native" SATA port and try again?





-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...