[K12OSN] Re: Load average sky-high but why????????

[dahopkins at comcast.net]

>dahopkins comcast net wrote:
>> After the rebuild of my systems here at NCS, the load average is
>> hitting 2+ with just a few users (4 or 5).  This is new behavior.
>> Using top, firefox seems to take alot of the CPU, as does StarOffice.

>Are you swapping? How much swap is "used":
>free -m

             total       used       free     shared    buffers     cached
Mem:          4056       3788        268          0         18        279
-/+ buffers/cache:       3490        566
Swap:         1984        158       1826

So, looks like not much swap is being used.

S>ome Firefox plugins can use copious CPU time (flash, JRE). Go to the
>URL "about:plugins" in Firefox. What's listed?

I have both Flash and JRE plugins installed.  

> Now, the system is also using software RAID 1.  I was leery about
> this but resorted to it because anaconda does not support my RAID
> card, and getting k12ltsp onto the system via other methods was also
> proving to be difficult.

Shouldn't be a problem. Linux MD is pretty fast; RAID1 is fast, no XORs
to compute. In top, are the CPUs mostly in us(user), sys(system),
ni(nice), id(idle), wa(iowait)?

The CPU's are mostly in id(idle).    As a test, I had a class of 30 log on at the same time, more or less.  Load average hit 32, us was about 75%,  sys was about 25%.  This is the worst case scenario, and this time didn't fail.  I see the same effect on logout.

Sincerely,
Dave Hopkins


Dan Young <dyoung mesd k12 or us>
Multnomah ESD - Technology Services
503-257-1562