'Disk Sleep' Problem

[Tom Lane]

Petrus de Calguarium <kwhiskerz at gmail.com> writes:
> For the last 3-4 days, I have noticed that my system will 
> intermittently hang and become unresponsive, then run again, 
> then hang, etc. Sometimes it is just for a bit, 
> occasionally, it is so bad that the hangs are about 98% of 
> the time, while running is only 2% or less of the time, so 
> bad that it takes more than 10 minutes just to get from an X 
> session to shutting off the computer.

> I had a glance at the system activity and I noticed that 
> some processes had 'disk sleep' next to them. Whenever the 
> computer began to run, this would change into a %cpu and 
> whenever the hangs occurred, 'disk sleep' would reappear.

It sounds to me like your disk drive is on the verge of failure:
it's taking a long time to process some read or write operations,
probably because it is retrying many times before succeeding.
You should look in the kernel log for evidence of problems, and/or
check the drive's SMART status if it supports that.

Back up your data immediately, and then see about replacing the drive.

			regards, tom lane