Sybase recommends that you set the number of available semaphore identifiers to at least 4096. To display the current values of the semaphore kernel parameters, use:
cat /proc/sys/kernel/sem
250 32000 32 4096
The four values displayed are:
SEMMSL – maximum number of semaphores per set.
SEMMNS – maximum number of semaphores system–wide.
SEMOPM – maximum number of operations allowed for one semop call.
SEMMNI – maximum number of semaphore identifiers (sets).
To adjust these values, and save them for future server restarts, edit the /etc/sysctl.conf file. For example, to increase the maximum number of semaphore identifiers to 4096, add the following line:
kernel.sem = 250 32000 32 4096
Make sure you leave one space before and after equals sign.
To make a change that lasts only until the next restart, use:
echo 250 32000 32 4096 > /proc/sys/kernel/sem
