Agonizingly slow SATA HDD performance

[Marcus D. Leech]

>
> On 09/13/2010 12:12 AM, Marcus D. Leech wrote:
>    
>> I have a new F12 system that is experiencing *agonizingly slow* SATA HDD
>> performance, and I
>>      can't figure out why.  No errors messages at all, just *really slow*.
>>      
> Sounds like a bad disk to me. Run some diagnostic with smartctl (from
> the smartmontools package). What does 'smartctl -H /dev/sda' return ?
> (replace sda by your disk name if it's different).
>
> What's the content of the error log ? (smartctl -l error /dev/sda) A
> non-empty error log is a good sign the disk is on the down curve.
>
> Next, run a quick self test (smartctl -t short /dev/sda), wait 2 minutes
> then check the result with "smartctl -l selftest".
>
> If that succeeds, run a long test (smart -t long /dev/sda), which takes
> about 2 hours.
>    
OK, I"ll check that out.

In the mean-time, this is a WD Caviar GREEN drive, which I understand 
has the intensely-brain-dead
   "feature" that it'll unload the heads after 8 seconds of idle, which 
may be part of the problem, since
   I have *lots* of spare memory, and the kernel only flushes every 30 
seconds, which means that
   it'll have to wait for the heads to re-load almost every time it flushes.

There's supposed to be a DOS-based utility from WD to change the timers 
(or turn them off).

I might end up buying a different drive!



-- 
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org