topic Shared Memory in Operating System - HP-UX

Shared Memory

Gerry Tully — Thu, 15 Jan 2004 12:06:44 GMT

I'm trying to run a program within a shared mem segment but I get the error 'trying to use shared file instead of shared memory' Also it says shmat: Permission denied. Everything else seems to be ok. Any ideas? Thanks.

Re: Shared Memory

Steven E. Protter — Thu, 15 Jan 2004 12:21:38 GMT

Details are needed to help you.

Waht kind of program, what is it supposed to do.

SEP

Re: Shared Memory

Gerry Tully — Thu, 15 Jan 2004 12:30:55 GMT

It is a Computron program related to a database that runs in it's own memory window.The first error that comes up is shmat failed for shared memory id 1faf, errno = 13.

Re: Shared Memory

Jean-Luc Oudart — Thu, 15 Jan 2004 12:44:21 GMT

Hi

would this thread be any help to you ?
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=98929

Rgds,
Jean-Luc

Re: Shared Memory

Gerry Tully — Thu, 15 Jan 2004 14:29:02 GMT

No, sorry that link didn't help. The funny thing is that I have development server that runs the program without a problem.

Re: Shared Memory

Jeff Schussele — Thu, 15 Jan 2004 14:47:36 GMT

Hi Gerry,

shmat() is the shared memory attach function & err #13 is EACCES or permission denied.
Sounds like the user trying to attach to the segment does not have the permissions to do so.
Check the users involved and/or whether the program trying to attach is running in the same window as the program that created the segment.

Rgds,
Jeff

Re: Shared Memory

Jim Butler — Thu, 15 Jan 2004 15:38:08 GMT

Try looking at the privgroup manpage -

you may need to allow privs to the processes

files are /etc/privgrp
/sbin/init.d/prv_grp (I think)

Anyway, if the computron program needs shared memory access, you may have to add the group in via privgrp and crank it up.

Really just a thought....

good luck

Re: Shared Memory

Gerry Tully — Thu, 15 Jan 2004 15:47:11 GMT

Thanks for the replies. I'm guessing it's a permission problem somewhere. Just have to find it.

Re: Shared Memory

Jeff Schussele — Thu, 15 Jan 2004 15:58:24 GMT

Hi (again) Gerry,

ALL programs that need to attach to that segment must be running in the same memory window as the program that created it.

Are you starting that computrom program using
setmemwindow -i window_id start_command
as the startup command?

Rgds,
Jeff

Re: Shared Memory

Gerry Tully — Thu, 15 Jan 2004 16:05:27 GMT

Jeff, Yes, that's how I am starting it.