how memory works

[Javier Ortiz Guajardo]

i have a unix 11.0 and i??m trying to understand how the memory works, i??m reading documentation about it from www.docs.hp.com.

I need more information about how the system works with the real memory, virtual memory, and memory swap. How the system assigns the size to each part of the memory (real, virtual, pseudo)?

Please, if you got information to share, you can send me to the email, jeortizg@hotmail.com

thanks so much.

[Uday_S_Ankolekar · Accepted solution]

Check for /usr/share/doc directory and look mem_mgmt.txt, mem_windws.txt and lot more

-USA..

[Robert-Jan Goossens]

Hi,

Try this link,

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062685991

Robert-Jan.

[Javier Ortiz Guajardo]

can somebody talk me about the Real memory and virtual memory?

Thanks.

[Steven E. Protter]

Real memory is actual physical memory.

Virtual memory is actually swap disk space that gets used just like memory to improve system performance capacity. It can do more things at the same time with more virutal memory.

Since virtual memory is disk, it is slower than real memory.

swapinfo -tam will show you something.


[597#] swapinfo -tam
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 4096 0 4096 0% 0 - 1 /dev/vg00/lvol2
reserve - 631 -631
memory 1526 1054 472 69%
total 5622 1685 3937 30% - 0 -

SEP

[Javier Ortiz Guajardo]

At this moment we can??t buy a product to monitor the system (like glance ...etc)
how can i evaluate my sistem with out this kind of tools, about memory and swap.

I need to knwo if my system is swaping and how much resources (Virtual memory, memory swap and real memory) is being used. Is there some commands that can help me to evaluate my system?

Can sar, vmstat, swapinfo. help me to evaluate my system?

i have a program - memdetail - but i??m having trouble to understand the results about this program.

i appreciate your help...
Thanks.

[malay boy]

This is another good threat for you question :

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x6f065ec05a7ad711abdc0090277a778c,00.html