""Sergey E. Koposov"" <math@sai.msu.ru> wrote
>
> selecting default max_connections ... 10
> selecting default shared_buffers ... 50
> DETAIL: Failed system call was shmget(key=1, size=1957888, 03600).
>
> selecting default max_connections ... 10
> selecting default shared_buffers ... 20
> DETAIL: Failed system call was shmget(key=1, size=1712128, 03600).
>
> selecting default max_connections ... 5
> selecting default shared_buffers ... 16
> DETAIL: Failed system call was shmget(key=1, size=1613824, 03600).
>
> To me it seems quite strange, since that behaviour does not relate with
> the formulae "250 kB + 8.2 kB * shared_buffers + 14.2 kB * max_connections
> up to infinity" from documentation.
>
If the linear relationship is still held, the shm formula induced from your
test is:
1384 kB + 8 kB * shared_buffers + 12.8 kB * max_connections
Seems in 8.1, the base shm requirement is increased. But I am not where they
are from.
Regards,
Qingqing