mysterious load

[Robert Brown <eli typhoon xnet com>]

I am experiencing a problem, the general form of which occurs from
time to time on various systems of mine.  The system shows a load, but 
top shows a virtually idle cpu:


 22:51:44  up  2:17,  2 users,  load average: 1.01, 1.01, 0.96
40 processes: 37 sleeping, 3 running, 0 zombie, 0 stopped
CPU states:   0.5% user   1.9% system   0.0% nice   0.0% iowait  97.4% idle
Mem:    60600k av,   48296k used,   12304k free,       0k shrd,    8708k buff
                     34744k actv,       0k in_d,     184k in_c
Swap:  522104k av,     252k used,  521852k free                   25896k cached


There are no nfs mounted filesystems.  This particular box is a
firewall, so it it dual-homed, and it runs l2tpd to establish a tunnel 
with a remote network, but that is only this particular instance.  I
see systems rom time to time that exhibit a load that is not
associated with any noticable cpu use.  I know the kernel can get
unhappy about certain resources other than just cpu utilization, but
how can I determine what is causing a load like this when the cpu is
idle? 

Generally, is there some well defined way to find what is throwing a
load on a box.  I guess a closely related questions is: How is "load"
computed?   If I knew all the factors that affect this mysterious
number, I would better be able to figure this out.

-- 
--------  "And there came a writing to him from Elijah"  [2Ch 21:12]  --------
R. J. Brown III  rj elilabs com http://www.elilabs.com/~rj  voice 859 567-7311
Elijah Laboratories Inc.    P. O. Box 166, Warsaw KY 41095    fax 859 567-7311
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