Long I/O pauses on same mass storage

[A. Wright]

On Wed, 12 May 2010, Adam Vande More wrote:

> On Wed, May 12, 2010 at 3:49 PM, Mike Tancsa <mike at sentex.net<mailto:mike at sentex.net>> wrote:
> At 04:27 PM 5/12/2010, A. Wright wrote:
> === START OF INFORMATION SECTION ===
> Device Model:     WDC WD15EARS-00S8B1
> Serial Number:    WD-WCAVY2700359
>
> Isnt that one of those Western Digital Green drives ? I seem
> to recall a number of people complaining about similar issues
> where the drive stalls. Perhaps a firmware update ? Or perhaps a
> way to disable the power saving/spin down features ?  Is your
> controller set to AHCI, or regular SATA. what does
> /var/run/dmesg.boot show ?

This is indeed one of the so-called "eco" drives.

The controller is set to SATA (no mention of ahci, though I will
now look at it as suggested earlier to see if I can control the
problem that way).


> In addition to what I pointed out earlier, I believe that is
> also a 4k sector drive.  You'll need to align your partitions
> accordingly.

As far as I can tell, it is a standard 512 byte sector.  The
general lack of documentation with this drive (shipped in a
plastic "coffin" -- the only docs supplied with it were the
label itself), but on the WD site, they indicate:
 	Formatted Capacity      1500301 MB
 	Used Sectors Per Drive  2930277168

Assuming a "megabyte" is 10^6 bytes, as is standard with
storage vendors
 	(1500301 * 1000 * 1000) / 2930277168 = 511.99968

So it appears that at least I don't have *that* particular
problem.

Thanks for the suggestions; I had not looked at AHCI before,
and it may well be part of my ticket out of this problem.

A.