One resource (for similar needs) can be found at
oracle's linux config pages. It covers raising shared memory, as well as increasing segment size & semaphores. Only warning is I think the segment defs moved .h files for 2.4; the oracle doc is written for 2.4. I'd also scan the HOWTOs, but I did a quick search and didn't find anything; your mileage may vary... There's a wealth of kernel docs out there, limited only by your stomach for it.
As an aside:
Your best option would be to use a recent 2.4 kernel (2.4.2 at the time I write this), where the shared memory limits are dynamically configurable at runtime.
An excellent point, but doesn't this answer merely transfer David's quest onto finding how to change these configs?
(So as not to call the kettle black:)
"echo '134217728' > /proc/sys/kernel/shmmax" raises shared mem max.
Some docs on /proc/sys/kernel/ are at linuxhq. I'm not sure how to play with semaphores in /proc; I haven't bothered to try.
