[mythtv-users] Horrendous RAID-6 performance

[Brad DerManouelian]

Yan Seiner wrote:
> John Drescher
>>>  Well, now that you mention it....  Nothing is using the system, but
>>> it's
>>>  still running at 67% wait states?  WTF?  What's it waiting for?  How do
>>> I
>>>  find the process that's waiting?
>>>
>>>  top - 15:18:08 up 2 days,  7:34,  2 users,  load average: 3.12, 3.66,
>>> 4.23
>>>  Tasks: 219 total,   2 running, 217 sleeping,   0 stopped,   0 zombie
>>>  Cpu(s):  3.1%us,  1.0%sy,  0.0%ni, 28.7%id, 66.8%wa,  0.0%hi,  0.5%si,
>>>  0.0%st
>>>  Mem:   2062908k total,  2046844k used,    16064k free,    18712k
>>> buffers
>>>  Swap:  3903712k total,   574648k used,  3329064k free,   720916k cached
>>>
>>>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>>>   7137 motion    20   0  259m  12m  792 S    6  0.6 369:57.08 motion
>>>   7376 root      20   0 1126m 100m  11m S    1  5.0  24:15.67
>>> mythbackend
>>>   7109 root      20   0  129m  50m 7148 S    1  2.5   4:21.79 Xorg
>>>   4960 root      15  -5     0    0    0 S    0  0.0   4:34.77 bond0
>>>   7399 root      15  -5     0    0    0 S    0  0.0   1:06.07 kdvb-fe-0
>>>     1 root      20   0 10392  664  632 S    0  0.0   0:04.14 init
>>>     2 root      15  -5     0    0    0 S    0  0.0   0:00.02 kthreadd
>>>
>>>
>> What is the motion process? And do you see your system is using 574MB of
>> swap?
> 
> motion is a motion detector program.  It monitors cameras and makes movies
> when it detects motion.
> 
> I get no change to the waitstates even with motion and myth dead....
> 
> I'm not sure why the system is using that much swap.
> 
> Could it be a tickless kernel problem?  I just went through the kernel
> config and that's the only thing I can think of that looks vaguely
> unusual.
> 
> --Yan
> 

Try using lsof to see what files are being accessed.