[Users] PostgreSQL can't allocate shared memory

[Kirill Korotaev]

Gregor Mosheh wrote:
> Hi, all.
> First: OpenVZ; nice. A slick alternative to VMWare, less overhead. Nice.
> But, a hitch in my first experiments...
> 
> I have PostgreSQL 8.1 in a VE (Fedora Core 6, for what it's worth), and I
> cannot set shared_buffers higher than 3700 (about 30 MB) and have it
> start. Anything higher and it complains that it can't allocate the shared
> memory.
> 
> In the UBC, I verified that I set shmpages to 32000, which should be 128
> MB at 4k apiece (or 256 MB if it's 8k pages; I'm not sure which it is for
> shared memory pages) and therefore more than enough for PgSQL's request. I
> have tried raising shmpages, but it doesn't change anything. The
> privvmpages is 262144 (1 GB) so this should also be plenty.
> 
> The UBC is showing 0 failcount across the board.
> 
> And the HN's kernel.shmmax is set to 1 GB. (Is that relevant in a VE?)
check the same in VE please.
AFAICS, by default kernel sets:
#define SHMMAX 0x2000000
which is 32Mb.
So you have to increase it in VE /etc/sysctl.conf file or in /proc.


> I'd be very appreciative of any help. And thanks for the software!
You are welcome!

Thanks,
Kirill