Subject: Re: [vserver] Shared Memory
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Thu, 29 Oct 2009 01:28:34 +0100

On Thu, Oct 29, 2009 at 01:20:12AM +0100, Holger Amann wrote:

> Am 29.10.2009 um 01:00 schrieb Lukasz Czarnowski:

> >I had the same experience with kernel 2.6.22.x-vs2.2.x and pgsql 8.1  
> >- shmem is counted several times.

> I played with the shared memory example shown at [1] and it seems,  
> that in general everything is working fine, except Postgres.
> So, until someone is able to fix this, Linux vServer and Postgres ->  
> Don't do it! :(

hmm, seems I'm still not understanding what the problem
is here, will read the thread again, in the meanwhile,
any hints are appreciated ...

TIA,
Herbert

> guest1:/# /etc/init.d/postgresql-8.4 start
> Starting PostgreSQL 8.4 database server: main.
> guest1:/# ipcs
> 
> ------ Shared Memory Segments --------
> key        shmid      owner      perms      bytes      nattch     status
> 
> ------ Semaphore Arrays --------
> key        semid      owner      perms      nsems
> 
> ------ Message Queues --------
> key        msqid      owner      perms      used-bytes   messages
> 
> guest1:/# ./shmserver
> 
> (from another console)
> guest1:~# ipcs
> 
> ------ Shared Memory Segments --------
> key        shmid      owner      perms      bytes      nattch     status
> 0x0000162e 65537      root      666        27         1
> 
> ------ Semaphore Arrays --------
> key        semid      owner      perms      nsems
> 
> ------ Message Queues --------
> key        msqid      owner      perms      used-bytes   messages
> 
> guest1:~# ./shmclient
> abcdefghijklmnopqrstuvwxyz
> 
> q.e.d.
> 
> [1] http://www.cs.cf.ac.uk/Dave/C/node27.html