Visit Our UNIX and Linux User Community


Linux Mem Usage


 
Thread Tools Search this Thread
Operating Systems Linux Linux Mem Usage
# 1  
Old 10-10-2007
Linux Mem Usage

What is amount of free RAM i have now?

Code:
              total       used       free     shared    buffers     cached
Mem:          1010        963         46          0        215        256
-/+ buffers/cache:        491        518
Swap:         1983          0       1983

Above is the output of 'free -m' from my linux machine. I did some searching on the internet and some of the articles point that linux is memory hungry ( not that it use up memory very fast, but it will use what is available). In my case, what is the free RAM i have? 46M or 518M. I highly do not think that its 46M + 518M.

The used and free Mem adds up to 1010 ( 963 + 46)

I am quite buffled by the -/+ buffers/cache value, the used and free values also adds up to 1010.

so linux is telling me it has used up 963MB of ram and 46MB is still available but on the other hand, it has 491 used in the buffer and 518 in the buffer is free... *confused and curious*

My total physical ram is 1GB. Would appreciate if anyone can explain and 'de-mysterifiy' me.
# 2  
Old 10-11-2007
Quote:
Originally Posted by new2ss
so linux is telling me it has used up 963MB of ram and 46MB is still available
But on the other had you have nearly 2Gig of swap it hasn't even touched.

Here would be an interesting test, start running more programs and see if it starts to use the swap file or whether it merely reduces the number of buffers available.

Previous Thread | Next Thread
Test Your Knowledge in Computers #714
Difficulty: Medium
Machine learning is a well known method for mitigating the Von Neumann performance bottleneck
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Help creating a timestamp script to record mem usage

Hi, I'm looking into doing a few performance tweaks by adjusting my max memory on a few lpars. I would to create a time stamp script so i could review it for a week and determine how much space i can lower my max memory to so i could reclaim and allocate that memory to where it is needed the... (2 Replies)
Discussion started by: vpundit
2 Replies

2. Programming

getgroups usage on linux

hi , I have a problem about getgroups usage on linux. getgroups can get supplementary groups of a process but if i run a process with root account and I want to get supplementary groups of nobody then what i should do to realize that. (4 Replies)
Discussion started by: fatshaw
4 Replies

3. Linux

Linux Device Driver: avoid mem copy from/to user/kernel space

I recently started working with Linux and wrote my first device driver for a hardware chip controlled by a host CPU running Linux 2.6.x kernel. 1. The user space process makes an IOCTL call with pointer to a user memory buffer. 2. The kernel device driver in the big switch-case of IOCTL,... (1 Reply)
Discussion started by: agaurav
1 Replies

4. AIX

How to monitor the IBM AIX server for I/O usage,memory usage,CPU usage,network..?

How to monitor the IBM AIX server for I/O usage, memory usage, CPU usage, network usage, storage usage? (3 Replies)
Discussion started by: laknar
3 Replies

5. UNIX for Advanced & Expert Users

Checking mem usage at specific times in a program

Hi all, I'm running a simulator and I'm noticing an slow increase in memory for long simulations such that the simulation has to end because of a lack of memory. A colleague of mine ran Valgrind memcheck and reported that nothing of interest was reported other than known mem leaks. My advisor... (2 Replies)
Discussion started by: pl4u
2 Replies

6. HP-UX

how can I find cpu usage memory usage swap usage and logical volume usage

how can I find cpu usage memory usage swap usage and I want to know CPU usage above X% and contiue Y times and memory usage above X % and contiue Y times my final destination is monitor process logical volume usage above X % and number of Logical voluage above can I not to... (3 Replies)
Discussion started by: alert0919
3 Replies

7. Gentoo

cpu%/mem% usage, scripting, dzen2: howto learn bash the hard way

I am trying to write a small (and rather simple) script to gather some info about the system and piping it to dzen2 first, i want to explain some things. I know i could have used conky, but my intention was to expand my knowledge of bash, pipes and redirections inside a script, and to have fun... (14 Replies)
Discussion started by: broli
14 Replies

8. Red Hat

Linux memory usage

What's the best way to find out how much memory is being used/available? I tried using free, but I didn't quite understand the output. Can someone explain it? $ free total used free shared buffers cached Mem: 16304536 16256376 48160 0 ... (6 Replies)
Discussion started by: junkmail426
6 Replies

9. UNIX for Dummies Questions & Answers

Difference in Mem usage ?

Hi All, I have a pair of sun ultra 5_10 with SunOS 5.5.1. Both are almost equally patched and set up with simillar applications. host# uname -a SunOS host 5.5.1 Generic_103640-24 sun4u sparc SUNW,Ultra-5_10 Even though both have same amount of RAM ( 512 Mb ) , ... (1 Reply)
Discussion started by: shibz
1 Replies

10. UNIX for Dummies Questions & Answers

Linux diskspace usage

when /var directory of my machine gets filled up (85%) i removed some old logs. but after cleaning df -k command still shows that /var is still 85% full. It can detect the actual disk space only after I restart the machine. Is there a way to force df to reflect actual free space without... (1 Reply)
Discussion started by: necro
1 Replies

Featured Tech Videos