> We are thinking about re-configuring our HP9000/F20(817) server so it can support
> more database instances. To do that, we have to increase the number of semaphores
> in the kernel. Currently, we have 150 on that machine(the default value in
> /etc/master file is 128). I am wondering by increase that number to 200 what would
> happen? Will the machine get slow? By how much?
> Yibing Wu
Increasing the number of semaphores would NOT slow down the system. The
only thing it does will be to take up more system memory and hence
decreasing the amount of lockable memory on your system. Just make sure
that you don't over-allocate the resources so much so that there is
no more lockable memory available, and you'll discover that some of
your applications/programs that need lockable memory (like glance and
nettl) would not run.
IRAS/CISB Unix Support Team