09-22-2005
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 234000 15358344
-/+ buffers/cache: 664032 15640504
Swap: 4194192 0 4194192
$ man free
$ free -m
total used free shared buffers cached
Mem: 15922 15877 44 0 228 15000
-/+ buffers/cache: 649 15273
Swap: 4095 0 4095
10 More Discussions You Might Find Interesting
1. HP-UX
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
2. UNIX for Dummies Questions & Answers
Hi ,
As I am new to Linux server, I am facing some doubts like: On linux server virtual memory usage goes to 99%, but I have Threshold limit of 95%. So it crossed the threshold limit and alarmd.
Yesterday I moniterd the server using TOP command, and found some of Tibco process was consuming... (1 Reply)
Discussion started by: Jaywantmm
1 Replies
3. Linux
Hi ,
As I am new to Linux server, I am facing some doubts like: On linux server virtual memory usage goes to 99%, but I have Threshold limit of 95%. So it crossed the threshold limit and alarmd.
Yesterday I moniterd the server using TOP command, and found some of Tibco process was consuming... (4 Replies)
Discussion started by: Jaywantmm
4 Replies
4. AIX
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. Shell Programming and Scripting
ok, so i'm trying to write a shell script (not perl) that monitors memory usage on a server. but i'm confused as to what fields exactly determines that yes, memory is low on a particular server.
it sounds simple enough, but it really isn't. what do I look for in the field below?
... (1 Reply)
Discussion started by: SkySmart
1 Replies
6. UNIX for Advanced & Expert Users
18:45:47 # free -m
total used free shared buffers cached
Mem: 96679 95909 770 0 1530 19550
-/+ buffers/cache: 74828 21851
Swap: 12287 652 11635
Hi all. The below output is from a RHEL 4.5... (0 Replies)
Discussion started by: drummerrob
0 Replies
7. Shell Programming and Scripting
I am looking for a way to log and graphically display cpu and RAM usage of linux processes over time. Since I couldn't find a simple tool to so (I tried zabbix and munin but installation failed) I started writing a shell script to do so
The script file parses the output of top command through... (2 Replies)
Discussion started by: andy_dufresne
2 Replies
8. UNIX for Advanced & Expert Users
Experts,
I have been trying to figure out what is the total physical memory used from this output:
And what is the free memory available for the application or any programs.
The answer has to be in this format:
1. Physical Memory Used= xx.xx%
2. Physical Memry available= yy.yy%
... (5 Replies)
Discussion started by: rveri
5 Replies
9. Red Hat
Hi ,
There is one following alert .
Message : cdm:Average (2 samples) swap memory usage is now 91%, which is above the warning threshold (90%)
Here is my findings.
Output of TOP command in Linux server.
top - 14:21:44 up 6 days, 4:48, 1 user, load average: 2.55, 2.06,... (3 Replies)
Discussion started by: Maddy123
3 Replies
10. Shell Programming and Scripting
Hello
We are in the process of migrating few of our applications in our linux boxes to new linux box to streamline our applications . In this context , i would like to know how we can calculate a particular application is used .?
This data will then be used to select which applications need... (7 Replies)
Discussion started by: ron5174
7 Replies
FREE(1) User Commands FREE(1)
NAME
free - Display amount of free and used memory in the system
SYNOPSIS
free [options]
DESCRIPTION
free displays the total amount of free and used physical and swap memory in the system, as well as the buffers and caches used by the ker-
nel. The information is gathered by parsing /proc/meminfo. The displayed columns are:
total Total installed memory (MemTotal and SwapTotal in /proc/meminfo)
used Used memory (calculated as total - free)
free Unused memory (MemFree and SwapFree in /proc/meminfo)
shared Memory used (mostly) by tmpfs (Shmem in /proc/meminfo, available on kernels 2.6.32, displayed as zero if not available)
buffers
Memory used by kernel buffers (Buffers in /proc/meminfo)
cached Memory used by the page cache (calculated as Cached - Shmem in /proc/meminfo - the Cached value is actually the sum of page cache
and tmpfs memory)
OPTIONS
-b, --bytes
Display the amount of memory in bytes.
-k, --kilo
Display the amount of memory in kilobytes. This is the default.
-m, --mega
Display the amount of memory in megabytes.
-g, --giga
Display the amount of memory in gigabytes.
--tera Display the amount of memory in terabytes.
-h, --human
Show all output fields automatically scaled to shortest three digit unit and display the units of print out. Following units are
used.
B = bytes
K = kilos
M = megas
G = gigas
T = teras
If unit is missing, and you have petabyte of RAM or swap, the number is in terabytes and columns might not be aligned with header.
-c, --count count
Display the result count times. Requires the -s option.
-l, --lohi
Show detailed low and high memory statistics.
-o, --old
Display the output in old format, the only difference being this option will disable the display of the "buffer adjusted" line.
-s, --seconds seconds
Continuously display the result delay seconds apart. You may actually specify any floating point number for delay, usleep(3) is
used for microsecond resolution delay times.
--si Use power of 1000 not 1024.
-t, --total
Display a line showing the column totals.
--help Print help.
-V, --version
Display version information.
FILES
/proc/meminfo
memory information
SEE ALSO
ps(1), slabtop(1), top(1), vmstat(8).
AUTHORS
Written by Brian Edmonds.
REPORTING BUGS
Please send bug reports to <procps@freelists.org>
procps-ng September 2011 FREE(1)