For 1024MB =
1024*1024*1024 bytes
kernel.shmmax=1073741824
and for ceil(1073741824)/4096) = 262144 which is actually much smaller than the setting that is the default ( 2097152 )
But setting these two to the values above still gives similar error and the pg-server still doesn't start.
2009-08-01 17:58:19 CESTFATAL: could not create shared memory segment: Invalid argument 2009-08-01 17:58:19 CESTDETAIL: Failed system call was shmget(key=5432001, size=1106247680, 03600). 2009-08-01 17:58:19 CESTHINT: This error usually means that PostgreSQL's request for a shared memory segment exceeded your kernel's SHMMAX parameter. You can either reduce the request size or reconfigure the kernel with larger SHMMAX. To reduce the request size (currently 1106247680 bytes), reduce PostgreSQL's shared_buffers parameter (currently 131072) and/or its max_connections parameter (currently 153). If the request size is already small, it's possible that it is less than your kernel's SHMMIN parameter, in which case raising the request size or reconfiguring SHMMIN is called for. The PostgreSQL documentation contains more information about shared memory configuration.
Increasing to
kernel.shmmax=1106247680 kernel.shmall=29250
doesn't seem to help either :
2009-08-01 18:09:55 CESTFATAL: could not create shared memory segment: No space left on device 2009-08-01 18:09:55 CESTDETAIL: Failed system call was shmget(key=5432001, size=1106247680, 03600). 2009-08-01 18:09:55 CESTHINT: This error does *not* mean that you have run out of disk space. It occurs either if all available shared memory IDs have been taken, in which case you need to raise the SHMMNI parameter in your kernel, or because the system's overall limit for shared memory has been reached. If you cannot increase the shared memory limit, reduce PostgreSQL's shared memory request (currently 1106247680 bytes), by reducing its shared_buffers parameter (currently 131072) and/or its max_connections parameter (currently 153). The PostgreSQL documentation contains more information about shared memory configuration.
but this does work :
kernel.shmmax=1106247680
kernel.shmall=2097152 (default value)
So I am guessing some manuals needs an update :P
/Jennifer