HP-UX Trying to Understand Shared Memory Segments

UNIX HP-UX
1

I am fairly new to HP-UX and trying to get a better understanding of the operating system. While poking around a bit I find myself questioning whether I should be concerned about Shared Memory segments with missing CPID and LPID? For example:

ipcs -mp
IPC status from /dev/kmem as of Mon Mar 17 12:36:43 2008
T ID KEY MODE OWNER GROUP CPID LPID
Shared Memory:
m 0 0x411c0846 --rw-rw-rw- root root 720 720
m 1 0x4e0c0002 --rw-rw-rw- root root 720 720
m 2 0x4120127e --rw-rw-rw- root root 720 732
m 48643 0x5e10000b --rw------- root root 2495 2495

The 720 PID is not found any longer. Is this necessarily a problem? The main reason I ask is that we have another server, much busier than this machine and while trying to identify how much shared memory is being used by various processes I have encountered other segments with missing CPID and LPID. Thanks in advance.

2

Not necessarily a problem, but probably a problem. A shared memory segment will not go away until explicitly removed. Most likely the process died without cleaning up. This is often caused by newbie sysadmins who jump into "kill -9". "ipcs -mb" will tell you how much memory is being consumed. "ipcrm" can get rid of it.

3

We have a few "kill -9" sysadmins. :smiley: This is something I will continue keeping my eye on. Thanks for the info.