Re: Postgresql error "pg_ctl stop" is invoked after a "postmaster

Carlo Florendo schrieb:
> I invoked:
>
> "postmaster -i -D /var/postgresql/data &"
>
> and was able to start and connect to my database. Since the process was
> made to run on the background, I wanted a way to stop it without doing a
> "kill -9". Thus, on another instance of my shell, I invoked :
>
> "pg_ctl stop -D /var/postgresql/data"
>
> Postgres says it was unsuccessful in shutting down the database.
> However, doing a "ps" revealed that no postgres processes were running.
>
> I then tried to restart the DB once again with:
>
> "postmaster -i -D /var/postgresql/data &"
>
> This time, I got this errror:
>
> $ postmaster -i -D /var/postgresql/data &
> FATAL: could not create semaphores: No space left on device
> DETAIL: Failed system call was semget(5432004, 17, 03600).
> HINT: This error does *not* mean that you have run out of disk space.
> It occurs when either the system limit for the maximum number of
> semaphore sets (SEMMNI), or the system wide maximum number of semaphores
> (SEMMNS), would be exceeded. You need to raise the respective kernel
> parameter. Alternatively, reduce PostgreSQL's consumption of semaphores
> by reducing its max_connections parameter (currently 40).
> The PostgreSQL documentation contains more information about
> configuring your system for PostgreSQL.
>
>
> I have a lot of diskspace. Doing a "df" revealed:

Now the tricky part:
Did you actually read what the error message told you?

Honestly, I know of no other POSIX or Windows app which explains such a
basic error in such helpful details. And I thought postgresql is already
ready for the dummy mode with the new windows port.

max_connections=40 is a bit high and your SEMMNS are way too low for 40.
5 are recommended for a busy system.

$ nano /etc/cygserver.conf
There you can edit the explained kernel params.

> $ df
...
--
Reini Urban
http://xarch.tu-graz.ac.at/home/rurban/

Reini Urban wrote:

> Carlo Florendo schrieb:
>
>> I invoked:
>>
>> "postmaster -i -D /var/postgresql/data &"
>>
>> and was able to start and connect to my database. Since the process
>> was made to run on the background, I wanted a way to stop it without
>> doing a "kill -9". Thus, on another instance of my shell, I invoked :
>>
>> "pg_ctl stop -D /var/postgresql/data"
>>
>> Postgres says it was unsuccessful in shutting down the database.
>> However, doing a "ps" revealed that no postgres processes were running.
>>
>> I then tried to restart the DB once again with:
>>
>> "postmaster -i -D /var/postgresql/data &"
>>
>> This time, I got this errror:
>>
>> $ postmaster -i -D /var/postgresql/data &
>> FATAL: could not create semaphores: No space left on device
>> DETAIL: Failed system call was semget(5432004, 17, 03600).
>> HINT: This error does *not* mean that you have run out of disk space.
>> It occurs when either the system limit for the maximum number
>> of semaphore sets (SEMMNI), or the system wide maximum number of
>> semaphores (SEMMNS), would be exceeded. You need to raise the
>> respective kernel parameter. Alternatively, reduce PostgreSQL's
>> consumption of semaphores by reducing its max_connections parameter
>> (currently 40).
>> The PostgreSQL documentation contains more information about
>> configuring your system for PostgreSQL.
>>
>>
>> I have a lot of diskspace. Doing a "df" revealed:
>
>
> Now the tricky part:
> Did you actually read what the error message told you?

Oh sheeesh! I'm so sorry. (How come I didn't see the hint?....sorry,
must've been my sleepiness.) No, I didn't read everything. And yes,
the explanation is really straightforward and to the point ( I realized
after I read it.) .

Apologies for the noise.

Thanks!

Best Regards,

Carlo

--
Carlo Florendo
Astra Philippines Inc.
www.astra.ph