Re: Problems with semaphores in Sun.

From: Javier Gonzalez <javierg_at_acm.org>
Date: 2000/03/08
Message-ID: <8a678n$veu$1@nnrp1.deja.com>#1/1

I am running Oracle 7.3.3 on solaris 2.6 soon to be Solaris 7 by tomorrow. I have 512Mb memory. the semaphores can be very tricky. I had the exact same error you did and I just had to play around with the setting till i got it right. I am also running a Sun 250.

my settings are as follows

set shmsys:shminfo_shmmax=393216000
set shmsys:shminfo_shmmin=1
set shmsys:shminfo_shmmni=100
set shmsys:shminfo_shmseg=30
set semsys:seminfo_semmns=1000
set semsys:seminfo_semmni=350
set semsys:seminfo_semmsl=350

i have 4 instances on my machine. I do have the following formulas for certain parameters.

shmmax - should be your physical memory * .5 - .8, it depends if all

         you have is running is oracle, if you have other compliers
         such as COBOL, or other big applications you should set the
         parameter lower to allocate memory for the other applications.
semmsl - set to 10 plus the largest init<sid>.ora (if you have multiple
         instances) processes parameter of an Oracle database.
semmns - set to the sum of the processes parameter for each of the
         Oracle db's except the largest one, plus 2 * the largest
         processes value, plus 10 * the number of oracle db's
     eg. if oracle_sid=a has 10 processes=100 oracle_sid=b has
         processes=100 and oracle_sid=c has processes=200, then

  semmns = ((a=100) + (b=100)+ ((c=200)*2) + ((# of instances=3)*10 =   630

In article <38BF8128.4322C08A_at_si.unirioja.es>,   Julio <julio.negueruela_at_si.unirioja.es> wrote:
> Hi all,
>
> We're migrating to Solaris from Digital and I've found a problem
 with t=
> he
> semaphores. As I'm trying to increase the processes more than 35 I get
 th=
> e
> following error at starting up my instance:
>
> ORA-07279: spcre: semget error, unable to get first semaphore set.
> SVR4 Error: 28: No space left on device
> Additional information: 1
>
> The documentation recomends the following:
> 07279, 00000, "spcre: error semget, no se ha podido obtener el primer
 con=
> junto
> de sem=E1foros."
> // *Cause: An error occurred when trying to get first semaphore set.
> // *Action: Check errno. Verify that system is configured to have
 semapho=
> res.
> // Verify that enough semaphores are available. Additional
 info=
> rmation
> // indicates how many semaphores were requested.
>
> In OSF had no problems with the default values for sempahores but
 we've c=
> hanged
> the following values, indicating the rest as default:
>
> set semsys:seminfo_semns=3D120
> set semsys:seminfo_semmsl=3D50
> set semsys:seminfo_semmni=3D30
> set semsys:seminfo_semmap=3D30
>
> We work with Oracle 7.3.4 in a Sun Enterprise 250 with Solaris 2.6
>
> Any help would be greatly apreciated.
> -- =
>
> Julio Negueruela
>
> 'Hay algunas cosas que son tan serias =
>
> que solo puedes bromear con ellas.' (Bohr)
>

--
Never be afraid to try something new.
    Remember amateurs built the ark.
       Professionals built the Titanic.


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Received on Wed Mar 08 2000 - 00:00:00 CST