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Linux memory usage


 
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Operating Systems Linux Red Hat Linux memory usage
# 1  
Old 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
# 2  
Old 09-22-2005
A good way at getting a quick overview is the top command (look at the top few lines of output).

$ top

Here's some (albeit RedHat) specifics that you will find useful
http://www.redhat.com/docs/manuals/l...y-rhlspec.html

Cheers
ZB
# 3  
Old 09-22-2005
Also keep in mind that Linux uses all available memory whenever it can for buffers and such. Memory not used is memory sitting around doing nothing, afterall. But it gives up the buffers when something else wants the memory. So don't panic when you see 100% of memory being used.
# 4  
Old 09-24-2005
Quote:
Originally Posted by junkmail426
tried using free, but I didn't quite understand the output.
Code:
$ cat /proc/meminfo

has a plain one
# 5  
Old 09-24-2005
Can try this, which will update the memory useage every 2 seconds. Open up a terminal and type

watch 'cat /proc/meminfo'
# 6  
Old 02-22-2006
In solaris, I use vmstat to see for high sr (Scan Rate) to detect memory deficiency.

What is the equivalent thing to do in redHat Linux Advanced server 3.0?
# 7  
Old 02-27-2006
Any Linux Expert here?

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