Hi, > Can I add SHM with merely by managing the entry in sysctl.conf? My > current values: > > kernel.shmmax = 536870912 > kernel.shmall = 536870912 > > My "shared_buffers" in postgresql.conf is "20000". From the website > http://www.desknow.com/kb/idx/12/061/article/ I notice that shmmax > should be sharedbuffer*8192, so I suppose my shmmax can be much lower > than the above, but I raised it for performance. Am I wrong to do so?
You need to configure the kernel so it allows processes to use more shared memory. This does not mean that a process automatically uses it. For PostgreSQL you will need to increase shared_buffers to make it use the extra available shared memory. With your shared memory settings you can probably increase shared_buffers to about 65000. With the 'ipcs' command you can see how much shared memory PostgreSQL uses. Look under 'Shared Memory Segments' to memory owned by user postgres. - Sander ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
