http://developer.postgresql.org/docs/postgres/kernel-resources.html
16.5.1
"FreeBSD"
...
$ systcl -w kern.ipc.shmall=32768
$ systcl -w kern.ipc.shmmax=134217728
$ systcl -w kern.ipc.semmap=256
"Linux"
...
$ systcl -w kernel.shmmax=134217728
$ systcl -w kernel.shmall=2097152
systcl is wrong sysctl notStefan