Re: Back in Production mode Again...

Simon's Mailing List Account (
Sat, 15 Nov 1997 16:44:54 -0500 (EST)

On Sat, 15 Nov 1997, James G. Stallings II wrote:

> My question involves load averages. When doing any intense disk I/O, with
> either the adaptec 2940-based Seagate Hawk, or the Triton II-based WD
> Caviar, the load average climbs dramatically; I've seen it go as high as
> 76.20!! and, believe it or not, the system didn't crash. Since then, I've
> written my scripts to sleep at startegic points during backup, and niced
> the embedded processes into oblivion, and the load avg only exceeds one at
> a couple of points over the run of the backup script.
> My question is this: what -is- a high load average? Over most of the
> period of a year of running this system as a production fileserver, The
> 'average' load average is probably near .25; so just what -are- reasonable
> loads on this system? (disk subsystems as described; dual P-166s, not
> overclocked; 32MB of crappy ram (we're cursed with the SIG-11 and so we
> compile off of this machine) on an older Tyan II Tomcat.

If you have sig11's you are probably getting all sorts of corruption
that is affecting load (i.e. bit flips in in-memory copies
of executables, kernel, etc), and such. Also, the Tomcat II
had a lot of problems with instability caused by bad COAST modules
and (apparently) parts of the board being quite 'noisy'.

Simon Karpen
Sysadmin, Shodor Education Foundation

"On two occasions I have been asked [by members of Parliament!], `Pray,
Mr. Babbage, if you put into the machine wrong figures, will the right
answers come out?' I am not able rightly to apprehend the kind of
confusion of ideas that could provoke such a question."
-- Charles Babbage