Re: SHMMAX, etc., for Oracle8 on Linux: Where to change?

From: please_no_spam <_at_france-mail.com(please_no_spam)>
Date: Mon, 07 Dec 1998 18:51:31 +0100
Message-ID: <74h50j$6bc$1@news.platinum.com>

On dejanews, searching SHMMAX, I found this: (maybe in this group)

---

/usr/src/linux should be linked to the kernel source used to configure your system.

Mine is symbolically linked as (BTW: I'm using the Redhat 5.1 distribution, the values shown here are the defaults)

/usr/src/linux -> /usr/src/linux-2.0.34/

/usr/src/linux/include/asm/shmparam.h contains:

#define _SHM_ID_BITS 7

 ...
#define SHMMAX 0x2000000 /* max shared seg size (bytes) */
#define SHMMIN 1 /* really PAGE_SIZE */ /* min shared seg size (bytes) */
#define SHMMNI (1<<_SHM_ID_BITS) /* max num of segs system wide */
#define SHMSEG SHMMNI /* max shared segs per process */
...
Which translates as:

SHMMAX = 33554432
SHMMIN = 1
SHMMNI = 128
SHMSEG = 128

/usr/src/linux/include/linux/sem.h:

#define SEMMNI 128 /* ? max # of semaphore identifiers */
#define SEMMSL 32 /* <= 512 max num of semaphores per id */
#define SEMMNS (SEMMNI*SEMMSL) /* ? max # of semaphores in system */
#define SEMOPM 32 /* ~ 100 max num of ops per semop call */
#define SEMVMX 32767 /* semaphore maximum value */

You can do the math there...

If these parameters aren't correct, you need to set them in the above listed include files and rebuild the kernel.

See /usr/include/linux/README for more info..

HTH --

Joe Brown                    -               Programmer
joebrown_at_leading.net         -                      DBA
joe@.hopi.dtcc.edu           -            Network Admin
http://users.leading.net/~joebrown     Have a Great day!!!
---------------------------------------------------------------------------------------

David Sisk wrote:

> Hi:
>
> The installation documentation for Oracle8 on Linux shows to change some
> shared memory parms, such as SHMMAX, SHMMNI, etc.  Where the heck are these,
> and how do I change them?  Could anyone point me in the right direction?
> Please email?
>
> Thanks and regards,
>
> --
> David C. Sisk
> http://www.ipass.net/~davesisk/ORACLEonNT.htm

Received on Mon Dec 07 1998 - 11:51:31 CST