Running out of IO threads

We have a couple of heavily loaded boxes here, with PII450, Linux
2.2.10-ac8, 5x9G 7200RPM SCSI, and squid 2.2stable3, compiled with
asyncIO and poll. The discs are used inividually (not RAIDed).

From time to time these warn about running out of IO threads. During
this event, there does not seem to be excessive IO happening. I have
re-built with double the number of threads (32?) with no help.
.

Any hints. I'm about to rebuild without async IO and see how it goes. I
also have modified main.c to not limit the max_fd's to fd_setsize when
using poll, but to use the ulimit value- maybe there is a select still
hanging around somewhre???

thanks,

--
Darren Steven
Applications Specialist
Networking Tasmania
Telstra Australia
Ph.1800 813 302