managing big executable on hpux 11i os

[Shivkumar]

Dear Sirs,

If a hpux system has 16GB RAM, and let us assume that there a software which has size of 17GB, then how the operating system manages such a big executable to load ?

Thanks,
Shiv

[A. Clay Stephenson · Accepted solution]

That is where virtual memory comes into play. Virtual memory is comprised of physical memory + swap space. The idea is that not all of the instructions or data need to be executed or acted upon at any one moment in time. Those that aren't needed are swapped out to disk but can be relaoded from disk as needed ---- but with a speed penalty.

[Arunvijai_4]

Hi Shiv,

You mean to say that the executable is of 17GB?. When you try to execute this file, swap area or memory comes into play. So, your virtual memory will be 16Gb+ Swap.

Hope this is clear.

-Arun

[Arunvijai_4]

Hi Shiv,

Some discussions in HPUX Devtools list,

http://h21007.www2.hp.com/dspp/ml/showArchiveMessage/1,,4!00!05!0046,00.html

-Arun

[Yogeeraj_1]

hi,

Virtual Memory.

see attached lecture notes

kind regards
yogeeraj

[Steven E. Protter]

Shalom,

Just because the software is a certain size does not mean it will use that much memory. It can use more or less.

My guess though is that it will use more, if it has any data. Thats quite a piece of software.

To a certain degree swap will help. After that a bigger memory pool may be needed. The OS uses some memory too.

SEP

[Arunvijai_4]

Hi Yogee,

I am experiencing difficulties opening the presentation. Powerpoint 2003 is crashing while i try to open. Can you resend it ?

-Arun
P.S : Zero points please.

[Muthukumar_5]

A good reference:

http://docs.hp.com/en/32650-90421/ch03s04.html

--
Muthu

[Muthukumar_5]

IT is not meant that if you are having 17GB sized executable then we have to have 17 GB RAM. HP-UX uses mechanism of paging of virtual memory. Every page will contain 4 KB size and it is used during the execution of executable.

We can find the usage of virtual memory as,

1) vmstat
2) swapinfo -tam will give all related memory informations.

--
Muthu

[Arunvijai_4]

Hi Shiv,

HP-UX memory management PDF is attached,

[Arunvijai_4]

Another great HP-UX 11i memory management White paper.

http://docs.hp.com/en/1218/mem_mgt.html

Shiv, I request you to join HP DSPP to access a great amount of tutorials and Tips in HP-UX.
http://www.hp.com/go/dspp.

Make sure you register and sign up for DSPP newsletter which is a great resource every month.

-Arun

[Yogeeraj_1]

hi again,

attached document is in pdf format

regards
yd

[Yogeeraj_1]

hi again,

attached document is in pdf format

regards
yd