How control the max use of memory?

[Jimmy Aulestia_2]

What is the best control for use of RAM memory in hp-ux?
I want to force the use to 50% of RAM and check the system, if the system and aplications works fine, then i will retire some dimms for another server.

[Geoff Wild]

Work Load Manager:

http://h20293.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=B8843CA

Rgds...Geoff

[Henk Geurts]

or PRM . Process Resource Management.
regards.
Henk

[Kent Ostby]

Here's a link for more data on PRM:

http://www.hp.com/products1/unix/operating/prm/manpages/prm.html

Oz

[Joel Girot]

HP GlancePlus (not free, but a trial version is available) gives useful information on the memory use.
It is necessary to supervise in particular the kernel parameters buffer cache (dbc_max_pct) and the vxfs inode cache (vxninode) which are, by defect, proportional to the memory size and are often oversize on the systems whose memory is significant.
Joel

[Jimmy Aulestia_2]

The PRM work when the use is 100% y want to reduce the total use of memory to 50%.

The dbc_max_pct and dbc_min_pct reduce the buffer. Are there any kernel parameter for redeuce the total memory use?

[NathanK]

You can collect information using measureware and see if you are ever using more than 50% of your memory.

[Bill Hassell]

HP-UX is a virtual memory system so you can remove a lot of RAM as long as there is enough swap space to run the required programs. Now you can limit specific users to not have more than a certain amount of RAM for each process but very few programs are smart enough to handle a ulimit memory ceiling and will simply crash. And typically the program will not tell you why it fails.

Now with lots of swap space, the programs can use whatever RAM they require, but performance may be pitifully slow. So there is no system-wide value to remove memory from usage.

[Bernhard Mueller]

Jimmy,

you can reboot, go through ISL and boot w/ -maxmem set:
ISL> hpux -maxmem ######

Most likely the number is the number of 4K pages I guess.

As this is an undocumented feature it may not work but I guess you would like to be able to test and adjust before physically removing DIMMs.

Regards,
Bernhard

[Bernhard Mueller]

Jimmy,

just tried it, looks like it does not work anymore....

Regards,
Bernhard

[Ted Buis]

I would think that you could turn off psuedoswap, and eliminate device swap space so that it is half of RAM. With pseudoswap off, memory would be deallocated. I think using PRM or WLM is a much better solution, but I think this would work.