Thread: How much shared memory am I using please?

How much shared memory am I using please?

From
adey
Date:
A "free" command on my linux server returns the following:-
 

                     total       used       free          shared    buffers     cached
Mem:       4077400    3958256     119144          0     104208    1551116
-/+ buffers/cache:    2302932    1774468
Swap:      2000084       4744    1995340

Postgres shared_buffers is set to 16384

SHMMAX is set to 256554432 bytes (245mb)

Why free show "shared" as 0 consistently please, and am I really not sharing any memory?

I'm trying to tune my SHMMAX parameter to provide an optimal shared memory segment size in which Postgres Shared_buffers can be optimised.

How do I do this please?