ATA trouble again

[Pegasus Mc Cleaft]

>Hello.
>
>This is a follow-up of a previous thread, which can be found here:
>
>> http://lists.freebsd.org/pipermail/freebsd-questions/2011-July/232257.
>> html
>
>
>
>I finally have two working WD Green drives: they have run severel times
>for more than a few days continuosly and I've run their full diags
>a few times over a span of some weeks, so I think I can be sure of that.
>Still I experience lot of troubles; however, trying different boxes, 
>I found out that these depend heavily on the controller I use.

Hi Andrea, 
	I don’t know if this will help you or not, but it may lead you to
another possibility. 

	I had a similar problem on my box (I was running 9.0-Current and 
Now 10.0-Current). I was also running under ZFS and would get TONS of 
Errors across my SATA drives. The errors would be anything from time-outs
to physical locking of the drive (I would have to pull the drive to let
the PHY on the controller reset and then plug the drive back in before
it would communicate with the machine again). In particular this would
happen when I was doing large writes to the drives. Read performance 
also suffered. I then created a single drive pool and did a large
transfer to the drive (about 800Gb) and the controller timed out again.
I moved the drive to various ports on the machine and also various
controllers in the machine. Some seemed to exabate the problem quicker
but no port or drive was safe from this. 

	I later found out that the drives I was using were using 4096
Bytes per sector. When I recreated the zpool using 4096 byte sectors
All the timeout errors disappeared and my data-rate has climbed
Dramatically. 


	Are you using ZFS or do you know if the drives are using 4096 bytes
Per sector?

Ta
Peg