[ubuntu-in] system has become unstable

[Rohit V Bhute]

Mehul Ved wrote:
> Have you run memtest on the RAM?
> My next suspect would be the hard disk? You can run smart and see what
> it returns. http://www.linuxjournal.com/article/6983
> 

'sudo smartctl -l error /dev/sda' gave a list of errors. Latest error 
recorded was 12.

http://pastebin.com/f32a37289

My other hard disk on /dev/sdb has ZERO errors. One pass in memtest gave 
ZERO errors in RAM.

Ubuntu forums is having a down time right now(!?), but a gist of google 
results imply impending disk failure...

Surprising thing is my machine works just fabulous when it is not acting up.

On going through /var/log/messages, I found the following log before the 
various restarts:

++
Aug  5 09:10:51 mark2 kernel: [   55.341694] Clocksource tsc unstable 
(delta = -236835484 ns)
Aug  5 09:15:43 mark2 exiting on signal 15
++

http://pastebin.com/f307b6625

On 5th August, between 8:30 to 10 AM and between 7:30 to 9:30 PM when 
the instability occurred, there was a bunch of these unstable messages.
-- 
Rohit V. Bhute
http://rvbhute.org