Problems setting shared_buffers to large value

Hi all,

I am running postgres 7.4.2 on a Dual processor Opteron with 16GB of ram. I want to set shared_buffers to a large value, but I am running into startup problems.

I have set my kernel SHMMAX and SHMALL to 12GB.

When I set shared_buffers to a value which puts the total shared memory usage over 1GB, my postgres server fails to start. Unfortunatly, I also cannot seem to get any logfile output out of my system (perhaps another question).

Are there any hardcoded max values for shared_buffers? I noticed in the code that a uint32 is used for the page size which would mean a 4GB max. This is failing at much lower values.

Sorry that I do not have a logfile output. Perhaps someone could help me turn my logfile on. I am passing –l logfile at startup, but my logfile remains empty.

Thanks in advance

Barry

(barry@GeipelNet.com