10-06-2005
Virtual memory: The use of a disk partition or a file on disk to provide the same facilities usually provided by RAM. A way of using disk storage space to make the computer work as if it had more memory. When a file or program is too big for the computer to work with in its memory, part of the data is stored on disk. This virtual storage is divided into segments called pages; each page is correlated with a location in physical memory, or RAM. When an address is referenced, the page is swapped into memory; it is sent back to disk when other pages must be called. The program runs as if all the data is in memory.
RAM: Random Access Memory. The working memory of the computer. RAM is the memory used for storing data temporarily while working on it, running application programs, etc. "Random access" refers to the fact that any area of RAM can be accessed directly and immediately, in contrast to other media such as a magnetic tape where the tape must be wound to the point where the data is. RAM is called volatile memory; information in RAM will disappear if the power is switched off before it is saved to disk.
This User Gave Thanks to RTM For This Post:
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
HP UNIX version 10.20
I have been using system variable names in some shell scripts in order to automate execution of some test software. I have recently found that there appears to be a restriction with the 'ls' command when listing specific files (e.g. ls *.c). If I pipe the output into wc, I... (5 Replies)
Discussion started by: degwright
5 Replies
2. Programming
Hi,
First of all I appreciate this group very much for its informative discussions and posts.
Here is my question.
I have one process whose virtual memory size increases linearly from 6MB to 12MB in 20 minutes. Does that mean my process has memory leaks?
In what cases does the... (4 Replies)
Discussion started by: shriashishpatil
4 Replies
3. Programming
Hi Folks
can any body suggest how to allocate virtual memory any function for that (2 Replies)
Discussion started by: munnu
2 Replies
4. HP-UX
Hi!
I work with HP-UX and I have to monitorize the use of virtual memory for different processes.
(java processes for Tibco Adapter) And if these processes exceed a limit send a message to the syslog.
I donīt know how to monitorize this...
Should I do a script? or use an aplication, for example... (3 Replies)
Discussion started by: Kurohana
3 Replies
5. AIX
Hi,
Would any one be so kind to explain me :
are ulimits defined for each user seperately ? When ?
Specialy what is the impact of :
max locked memory
and
virtual memory
on performance of applications for a user.
Many thanks.
PS :
this is what I can see in MAN :
ulimit ]
... (5 Replies)
Discussion started by: big123456
5 Replies
6. UNIX for Dummies Questions & Answers
Hi All,
Does anyone know what the best commands in the UNIX command line are for obtaining this info:
current CPU usage
memory usage
virtual memory usage
preferably with date and time parameters too?
thanks
ocelot (4 Replies)
Discussion started by: ocelot
4 Replies
7. UNIX for Dummies Questions & Answers
Hi,
Can anyone please help me workout how much virtual memory I have running on a T2000 running Solaris 10. Thanks
# df -h
swap 3.5G 1.0M 3.5G 1% /etc/svc/volatile
swap 3.5G 208K 3.5G 1% /tmp
swap 3.5G 56K ... (2 Replies)
Discussion started by: jamba1
2 Replies
8. Linux
Hi all,
I was compiling my glibc 2.6.1 source files on a new kernel 2.66.22.6 and it seems that i am running into issues with the Virtual Memory. It displays the error message:
virtual memory exhausted: Cannot allocate memory
I saw an article on how to adjust the parameters but i can't... (5 Replies)
Discussion started by: scriptingmani
5 Replies
9. UNIX for Advanced & Expert Users
Hi Experts
I encountered a situation recently. I wanted to discuss here and understand the reason behind this. My scenario is something like this:
yes > temp &
The above command keeps writing the output to the file temp. And this file keeps growing every second. And in the every... (4 Replies)
Discussion started by: guruprasadpr
4 Replies
10. Solaris
Hi All,
Please explain me about Virtual Memory.
Regards,
SKumar (1 Reply)
Discussion started by: nskumar
1 Replies
LEARN ABOUT DEBIAN
vzcalc
vzcalc(8) Containers vzcalc(8)
NAME
vzcalc - calculate resource usage of a container
SYNOPSIS
vzcalc [-v] CTID
DESCRIPTION
This utility displays the share of the host system resources a particular container is using. If the container is running, the current
usage is displayed. High utilization values (>100%) mean the system is overloaded (or the container has an invalid configuration).
Current
Shows the amount of the resources consumed by the container at a given time.
Promised
Shows the resources soft limit values "promised" for a given container.
Max Shows the resources hard limit values "promised" for a given container.
If the -v option is specified, the following additional information is also displayed:
Low Mem
The part of memory residing at lower addresses and directly accessed by the kernel (only makes sense for 32-bit architectures).
Total RAM
Total memory.
Mem+Swap
Amount of memory available for applications (both RAM and swap space).
Alloc Mem
Standard memory allocations made for applications in a container. This is a more "virtual" system resource than RAM or RAM and
swap.
Num. Proc
Number of processes.
OPTIONS
-v Display additional information.
EXIT STATUS
Normally, the exit status is 0. On error, the exit status is 1.
LICENSE
Copyright (C) 2000-2009, Parallels, Inc. Licensed under GNU GPL.
OpenVZ 10 Dec 2009 vzcalc(8)