How do I increase the number of semaphore arrays in Linux? In a Debian lenny server running postgresql, I noticed that a lack of semaphore arrays is preventing Apache from starting up. Looking at the limits, I see 128 arrays used out of 128 arrays maximum, for semaphores. I know this is the problem because it happens on a `semget` call. How do I increase the number of arrays? PS: I need Apache running to make use of phppgadmin.

If you read the manpage for semget, in the Notes section you'll notice:

> System wide maximum number of semaphore sets: policy dependent (on Linux, this limit can be read and modified via the fourth field of `/proc/sys/kernel/sem`).

On my system, `cat /proc/sys/kernel/sem` reports:


250 32000 32 128


So do that on your system, and then echo it back after increasing the last number:


printf '250\t32000\t32\t200' >/proc/sys/kernel/sem


(There are tab characters between the numbers, so I'm using `printf` to generate them.)