virtual memory

[SSP_1]

Hi Guys,

I have grouped the applications in glance's parm file and now if I view the processes for oracle user it shows me the size of virtual memory as 28.4 GB whereas total swap space on this server is 14 GB and physical memory of the server is 3.5 GB. Can anybody pl explain howz the virtual memory so hugh and also the Resident mem which is 4.99 GB
Below is the output derived from glance for user oracle.

oracle_user 229 103 35.0 37.4 49.6 75.9 4.99gb 28.4gb

[T G Manikandan]

What version of glance you are running and pls.check you have the latest patches for the version

Thanks

[Steven E. Protter]

swapinfo -tam

Memory equals swap plus physical memory.

If the figure does not agree with that, then its patch time.

SEP

[A. Clay Stephenson · Accepted solution]

I would look for and apply the latest Glance/MeasureWare patches BUT this is entirely possible. Memory usage calculations are far from trivial when they apply to a group of processes. Each process has it's own private data area but many processes can share text (the instructions) and functions within shared libraries are shared. In addition, many processes can attach the same shared memory segments. Each instance of these multiple uses contributes towards the total memory usage for this group of processes. Some memory segments may be counted many, many times --- and that is how you can seem to be using much more memory (virtual or otherwise) than you actually have.

[twang]

You may take a look at this document /usr/share/doc/mem_mgt.txt.Z

[SSP_1]

Hi Guys,
The glance version is
B3692A GlancePlus C.02.30.00


One thing I haven't done mwa restart after configuring my /var/opt/perf/parm file. This is a prod server and for each change we have to raise a change so I am afraid if restart of these services may affect any other applications. Is it feasible to restart the mwa when the applications are up 7 live and in init 3 mode.

[James Randall]

To apply the parm file...you need only restart the SCOPE collector:

(Make sure no glance or gpm sessions are running)

mwa restart scope

This will bounce both the scope collector and the mideamon. (Thus applying your change)

[PIYUSH D. PATEL]

Hi Sripad,

Measureware restart will not cause any problems to the applications. Instead of restarting the MWA application or all the processes through "mwa stop" and then "mwa start" you could just restart scopeux by "mwa start scope". Henec scopeux would re-read the parm file.

HTH,
Piyush

[Witter]

hi,

this not a problem about your glance version.
oracle processes uses shared memory. so each oracle process hold the total sga-size of his oracle instance as virtual memory. you can see this in glance, when you look for the memory regions for each process. the size for "Shmem VSS" is always the total sga-size. so your 229 oracle-user. each of them uses the total sga-size, so the addition of all the process is always a very high value, which does not belong to the total swap space, because it's shared memory.
i hope this help's