Record High Load Average

[Rene' Seindal]

brian at ucsd.EDU (Brian Kantor) writes:

> A few years ago our Vax-780 'sdcc3' set the netwide load average record
> high of 128 (and may still hold it for a single-processor Unix system).

> Yesterday we got our network connections unjammed and our mail gateway
> 'UCSD' set what I think may be the record for a Vax-750: 85.3.  And this
> is on a machine which has NO users, just sendmails.  Thank goodness
> we're getting some faster hardware in soon.

I have seen a load of more than 200 on a Vax-785.  A hard error on a disk made
every process using the disk hang in disk i/o.  Because disk i/o is usually
short-termed, the processes still added to the load, even though they didn't
consume any cpu.

Talking to the machine became more and more difficult, as more and more
daemons got stuck too.  At a point we could only do rsh's to it, and only run
certain programs (whose that didn't touch the sick disk, which had /tmp on
it!).  Every time you made a mistake, one or two processes more would get
stuck, increasing the load further.


Rene' Seindal (seindal at diku.dk).