topic Re: chown shared memory? in Operating System - HP-UX

chown shared memory?

Andy McDade — Fri, 12 Apr 2002 08:07:37 GMT

Is there any way of changing the ownership of a shared memory segment? At the moment we have an application which uses a fairly large chunk of shared memory, and doesn't always get created by the right user. We have to remove the segment and reinitialise it using the correct user - if there was a utility to change the ownership that would be great.

Re: chown shared memory?

Paula J Frazer-Campbell — Fri, 12 Apr 2002 08:12:08 GMT

Andy

Instead of fixing the end result why not fix it at source.

Get the software guys to do the job correctly.

Paula

Re: chown shared memory?

Clemens van Everdingen — Fri, 12 Apr 2002 08:15:16 GMT

Hi,

I don't believe we can chown shared memory, but why doing this ?
Solve the problem why it gets the wrong owner !
Ask the programmers to do their job. This instead of you fixing their problems.

C.

Re: chown shared memory?

Andy McDade — Fri, 12 Apr 2002 08:29:07 GMT

If only I could. The developers have "many more important" things to do before getting around to this. I want to make my life easier in the (posisbly very long) meantime.

Re: chown shared memory?

Clemens van Everdingen — Fri, 12 Apr 2002 08:36:04 GMT

Hi,

As I already said, I don't think it can be done on OS level. It has to be done on program level.

C.

Re: chown shared memory?

Paula J Frazer-Campbell — Fri, 12 Apr 2002 08:44:27 GMT

Andy

If the ownership of this shared memory causes a problem then options:-

1. Get Dev to fix it.
2. Fix as you are doing.
3. Change user profiles/groups so that there is no ownership problem.
4. Put script in place to pick up the wrong ownership and either fix it / zap the user or send out warning.

5. Option the last - forget about it - Its Friday the sun is shining and the Pubs are open.

;^)

Paula

Re: chown shared memory?

Clemens van Everdingen — Fri, 12 Apr 2002 08:49:02 GMT

Paula,

The last option is the best :-)

Clemens

Re: chown shared memory?

Paula J Frazer-Campbell — Fri, 12 Apr 2002 08:51:31 GMT

Hi

As Andy is from the UK I thought he would appreciate that.

;^)

Paula

Re: chown shared memory?

Roger Baptiste — Fri, 12 Apr 2002 08:52:26 GMT

hi,

I don't think it is possible on an existing shared memory being used. You have to do it at the source level.

HTH
raj

Re: chown shared memory?

Deepak Extross — Fri, 12 Apr 2002 09:08:58 GMT

Andy,
Not sure if there's a tool out there yet, but you can roll-your-own utility to do this using shmctl().
man shmctl for details.
But as others have pointed out, this is best addressed by the developers.

Re: chown shared memory?

Steve Lewis — Fri, 12 Apr 2002 10:50:35 GMT

Why not create a new group, which the owner process/user and all attachers to the segment are a member of?

If you do ipcs -ma you see owner and group permissions listed. Surely grouping them all together will fix it.