How to increase Shared memory segments

How to increase Shared memory segments

Post by Mitchell Nemet » Fri, 19 May 2000 04:00:00



Greetings to everyone.

I found procedural notes in the Online System Administration Guide, Volume
2.

My understanding is backup /etc/system before proceding, and enter the
statements to set the desired variable and value, save the file, verify the
changes are correct, and reboot.

Example: set shmsys:shminfo_shmmax=value ; etc.

The rebooted system should pickup the new values from /etc/system.

What I experienced instead was, the system picked up the changes I entered
for "shmsys:shminfo" parameters shmmax, shmmin, shmmni, and shmseg
perfectly. just as advertised. BUT the "semsys:seminfo" parameters semmap,
semmni, semmns, semmsl, semmnu, and semume did not pick up the new values
entered into /etc/system AND not only that but the IPC Semaphores Module did
not load. (as displayed by the output of "sysdef")

I restored the original /etc/system, and rebooted.
the shared memory parameters returned to their defaults, but the Semaphores
did not, and also did not load.

So, I am now wondering, did I "break" something?, and am posting here to see
if I can get advice on how to get back on track.

E 250, 1024MB RAM, Solaris 8

Thanks very much,
Mitchell Nemeth

 
 
 

How to increase Shared memory segments

Post by Frank Braue » Fri, 19 May 2000 04:00:00


Hi Mitchell,

I'm not sure that sysdef shows the correct (maximum) value. Have you tried
to start a application which uses the semaphores/shared memory?

Frank

 
 
 

How to increase Shared memory segments

Post by Mitchell Nemet » Fri, 19 May 2000 04:00:00


Good question!
No I haven't yet received my product. I am preparing this box in advance.
The perplexing part is that sysdef DOES show the shmseg values I entered in
/etc/system correctly, and ALSO displays "The IPC Semaphores module did not
load"


Quote:> Hi Mitchell,

> I'm not sure that sysdef shows the correct (maximum) value. Have you tried
> to start a application which uses the semaphores/shared memory?

> Frank

 
 
 

How to increase Shared memory segments

Post by Andrew Gabri » Fri, 19 May 2000 04:00:00




Quote:> BUT the "semsys:seminfo" parameters semmap,
>semmni, semmns, semmsl, semmnu, and semume did not pick up the new values
>entered into /etc/system AND not only that but the IPC Semaphores Module did
>not load. (as displayed by the output of "sysdef")

System only loads these modules when they are first used, so all this
means is you haven't used them yet. Nothing wrong.

--
Andrew Gabriel
Consultant Software Engineer

 
 
 

How to increase Shared memory segments

Post by Tony Walto » Sat, 20 May 2000 04:00:00



> Good question!
> No I haven't yet received my product. I am preparing this box in advance.
> The perplexing part is that sysdef DOES show the shmseg values I entered in
> /etc/system correctly, and ALSO displays "The IPC Semaphores module did not
> load"

I've not come across the "did not load" message - did it really say

"IPC Semaphores module is not loaded"?

See if it's really loaded or not by doing

modinfo | grep XXXsys

Replace XXX by "sem", "shm" or "msg" as appropriate in the grep command
above.

You could also try forcing the appropriate module to load by saying

modload -p sys/XXXsys

at the root prompt (XXX being "sem", "shm" or "msg" as appropriate).
The module will then be loaded until the next reboot.

It's also possible to force the module(s) to load at boot time
automatically - add

forceload: sys/XXXsys

to /etc/system (XXX as above)

I've never quite seen the point of doing this, myself - YMMV.

--
Tony