[Lxc-users] postgres

[Papp Tamas]

hi!

I want to increase shared_buffers value.
Machine has 8GB of RAM.
OS is Ubuntu Precise on both host and container.

kernel.shmmax = 2147483648
kernel.shmall = 2147483648
kernel.shmmni = 4096


Originally the maximum value was 25M, I don't know how, but I could 
increase it until 29M.
It starts fine with shared_buffers = 29M .

With 30M:

  * The PostgreSQL server failed to start. Please check the log output:
2012-05-12 20:37:19 UTC FATAL:  could not create shared memory segment: 
Invalid argument
2012-05-12 20:37:19 UTC DETAIL:  Failed system call was 
shmget(key=5432001, size=34455552, 03600).
2012-05-12 20:37:19 UTC HINT:  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 
34455552 bytes), reduce PostgreSQL's shared memory usage, perhaps by 
reducing shared_buffers or max_connections.
     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.
                                                                                                                                                                                                             [fail]


If I chroot to the container from the host it just works as expected.

Any idea?

Thanks,
tamas