performance under heavy load

Phil Brennan phil.brennan at
Sat Mar 5 16:28:10 GMT 2005

Hi, I'd just like to give some credit to the freebsd developers for a
job well done.
A user on our system ( freebsd 5.2.1 smp )  managed with a runaway
script to start up 500 intensive processes, raising the load average
to about 200.
We managed to remotely, over ssh get a somewhat responsive session and
kill the offending processes. Yes, I know we shouldn't have let it
happen in the first place, by putting in proper user limits and all
that, but it was amazing that the machine still worked. We thought
we'd have to reboot. Even with a load of nearly 200, the machine was
still able to serve web pages :)
Once the load came down past 60, the system feltl fully responsive again.
On linux, we would have had to reboot in this situation. On a highly
linux machine, you lose all control of the machine past a load of
about 6 - 10. This just further vindicates my decision to use freebsd
for this service. ( Its a shell server with about 100 active users,
apache, nfs, mysql, ldap ). Just wanted to share a success story :)

Philip Brennan

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