I'm using postgresql 9.1 as my database server on a linux server that has 8 GB of RAM.
After I changed the shared_buffers parameter to 2GB, I get the following error when I try to start postgres:
FATAL: could not create shared memory segment: Cannot allocate memoryDETAIL: Failed system call was shmget(key=5432001, size=2221539328, 03600).
Here are the shmall and the shmax params of my server:
#cat /proc/sys/kernel/shmmax 68719476736
#cat /proc/sys/kernel/shmall 4294967296
So as you see, shmall is greater than the requested size by postgres. Anyone have and idea?