shared memory question 1

[stu78]

Hi,

Is it possible to adjust the shared memory on solaris boxes without requiring a recycle of the server?

any ideas,
stu

 

[jamisar]

what's: 'adjust the shared memory'
what's: 'recycle' my be reboot ?? -----------
when they don't ask you anymore, where they are come from, and they don't tell you anymore, where they go ... you'r getting older !

 

[stu78]

Sorry for not making my question clearer jamisar,

What I need to do is tune the shared memory segments on the solaris system - such as the;

shmsys:shminfo_shmmax
semsys:seminfo_semmnu

located in /etc/system

However since this is a heavily used system I do not wish to reboot the server unless necessary. Is there any other options to tune these shared memory segments without rebooting the box.

Thanks for any ideas.

 

[Annihilannic]

You have to reboot the server. Annihilannic.

 

[stu78]

Thanks for the reply Annihilannic,

I was hoping there would be some other solution, If anyone knows any other option; please let me know.

Stu

 

[AIXSPadmin]

Yeah, move to AIX - the shared memory segments cannot be changed so you don't have to reboot your sever.

 

[stu78]

Thanks for such useful information, AIXSPadmin

 

[MikeLacey]

It's a nuisance but you have to guess plan the amount of shared memory you will need on *most* UNIX systems. I started with Solaris, moved to AiX and when I cam back to Solaris remembered what a pain it was.... Mike

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[rycamor]

>>you have to guess plan the amount of shared memory you will need on *most* UNIX systems.

Really? Are you saying that even now most commercial UNIX systems don't allow dynamic shared memory adjustment?

Man, another reason to keep loving FreeBSD (BSDI too?):

su-2.04# sysctl -w kern.ipc.shmmax=37748736
kern.ipc.shmmax: 25165824 -> 37748736

(Just adjusted shared memory max from 25165824 to 37748736) -------------------------------------------

Big Brother: "War is Peace" -- Big Business: "Suspicion is Trust"
(

http://www.cl.cam.ac.uk/~rja14/tcpa-faq.html)

 

[dblair]

..and HP-Compaq Tru64

 

[MikeLacey]

Ah.... thx rycamor Mike

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[Boria]

Hi Stu,
there are two good command to solve shared memory problem.
ipcs - to see all shared memory segments.
ipcrm - to free not used shared memory segments.
Regards Boris

 

[art15t]

if you've ever managed development servers then you will come across this problem quite often(damn and blast those developers) :-}

Are you familiar with the day-to-day owners of the shared memory segments? Then you can identify and flush out shared memory with ipcs -a and grep -v the shared memory users who you don't wan't to work with. then it's a simple case of grabbing the shmid keys of the grep and using ipcrm -s and ipcrm -m to clean and grab back those chunks of memory and make them available to more pressing applications/users.

...but be careful, you really need to be sure on this!

Ok so Solaris needs a reboot but this is a good time to manage those other quickies that a busy business won't normally give you the time to perform.

ART