topic Re: HP UX minimum needed RAM in Operating System - HP-UX

HP UX minimum needed RAM

Bayu — Tue, 15 Jul 2008 07:16:24 GMT

Hi all,

My HP UX box is eating approx 26% of its Physical RAM (for a total 4 Gigs is more than 1 Gigs used) when the server just started (no additional services started).

I just found somewhere that HP UX minimum RAM requirement is 128MB, so I think there's some or most services can be stopped to free the mem.

using sam, in network services, I only enabled the FTP server, the other is disabled. Can any of you suggest me how I can free the memory, to reach the minimum required memory?

I only needed ftp and ssh network service. I'm using VxFS.

TIA

Re: HP UX minimum needed RAM

Jeeshan — Tue, 15 Jul 2008 07:38:49 GMT

check the kernel parameters value

dbc_max_pct
dbc_min_pct

Re: HP UX minimum needed RAM

Dennis Handly — Tue, 15 Jul 2008 08:43:19 GMT

If you already have 4 Gb, you have 32 times 128 Mb. Also, I doubt 128 Mb is the minimum for 11.23 or 11.31.
Basically what is important here is swapspace. What is "swapinfo -tam"?

Re: HP UX minimum needed RAM

Bayu — Tue, 15 Jul 2008 10:36:54 GMT

ahsan: thanks, I'll check the result soon.

dennis: afaik, the swap will not be used if the physical memory is still avalaible, and my concern is how to minimize the OS usage of Physical Memory, but thanks for your suggestion..

Re: HP UX minimum needed RAM

Dennis Handly — Tue, 15 Jul 2008 10:43:17 GMT

>my concern is how to minimize the OS usage of Physical Memory

If this can be swapped out, then you don't worry too much about this and add device swap.

Re: HP UX minimum needed RAM

Bill Hassell — Tue, 15 Jul 2008 10:51:40 GMT

HP-UX is a virtual memory system so if you physically remove all but 128 MB of RAM, the system might possibly bootup (very, very dependent on your HP_UX version and what you have in the kernel as far as drivers and kernel parameters). But performance will be awful because everything you try to do will likely require swap space.

I think you may have misunderstood the 'minimum' requirement. If you are trying to reduce the memory that is currently used by the processes and the kernel, you must stop all services. Look in /sbin/init.d/ for the service list. If you wnat to see what processes are using RAM, use this command:

UNIX95=1 ps -eo vsz,pid,ppid,args | sort -rn | head -20

That sorts the processes by memory used. But what is the purpose to reduce memory? You have 4Gb so you have plenty of memory for typical applications. Are some of your programs getting "out of memory" or errno 12 messages? These error do not refer to physical RAM at all. They refer to the program's ability to request additional memory and for archaic 32 bit programs, there are severe limitations for the maps used by such programs.

The kernel may also have several parameters that are far too large (ninode, dbc_max_pct, dbc_min_pct), possibly drivers that are not needed.

Re: HP UX minimum needed RAM

Steven E. Protter — Tue, 15 Jul 2008 11:31:20 GMT

Shalom,

Actual memory requirements vary per version.

HP-UX 11.00 probably would run in some kind of slow awful way in 128 MB of RAM.

As the version number increases the memory requirement increases.

Since you don't state your version, there is not an answer possible to your question.

SEP

Re: HP UX minimum needed RAM

Torsten. — Tue, 15 Jul 2008 11:36:58 GMT

hp-ux 11.31 needs 1,5GB minimum, see

http://docs.hp.com/en/5992-3364/ch02s01.html

What version do you have?