Server Memory Usage (script)

[thisisit3]

Ever wondered how much memory you are currently using and how close you are to the QoS hard limit?

Here is a simple script that calculates the QoS hard memory limit and the current memory usage:

#!/bin/sh

# Make sure we are running under a VPS system with QoS
if [ ! -f "/proc/user_beancounters" ]; then
	echo "File \"/proc/user_beancounters\" does not exist. Make sure this script runs on a VPS system with QoS enabled."
	exit $E_NOFILE
fi

# Get memory related variables
let GMEM=`grep vmguarpages /proc/user_beancounters | awk '{print$4}'`/1024*4
let BRST=`grep privvmpages /proc/user_beancounters | awk '{print$5}'`/1024*4
let CMEM=`grep physpages /proc/user_beancounters | awk '{print$2}'`/1024*4
let REQM=`grep privvmpages /proc/user_beancounters | awk '{print$2}'`/1024*4
let FREE=$GMEM-$CMEM

# Calculate free memory
if [ "$FREE" -gt "0" ]; then
	let CMEMP=$CMEM*100/$GMEM
	let FREEP=100-$CMEMP
else
	let CMEMP="100"
	let FREEP="0"
fi

let REQMP=$REQM*100/$GMEM

# Calculate pretty output
if [ ${#CMEM} -gt ${#FREE} ]; then
	let LIMIT=${#CMEM}-${#FREE}
	SPACE=''
	while [ $LIMIT -gt 0 ]; do
		SPACE=" $SPACE"
		LIMIT=`expr $LIMIT - 1`
	done
else
	SPACE=''
fi

# Echo results
echo "Memory limit...: $GMEM MB (burstable: $BRST MB)"
echo "Requested......: $REQM MB (${REQMP}%)"
echo "Current usage..: $CMEM MB (${CMEMP}%)"
echo "Free memory....: $FREE MB ${SPACE}(${FREEP}%)"

Create the directory ~/bin, then save the above code as "vmem" inside that directory and "chmod +x ~/bin/vmem" to make it executable. Now edit your ~/.bashrc, and add "~/bin/vmem" at the end, thus you'll get a memory report every time you login, or every time you type "vmem" in the shell.

v5 - New: Better display of requested memory usage
v4 - New: check for VPS, clean code, comments
v3 - New: adds 'bustable' & 'requested' memory...
v2 - New: adds 'free' memory and percentages...

[Cygnus]

Very usefull, thanks!

[AlexKall]

#!/bin/sh

let GMEM=`grep vmguarpages /proc/user_beancounters | awk '{print$4}'`/1024*4
let CMEM=`grep physpages /proc/user_beancounters | awk '{print$2}'`/1024*4
let FMEM=$GMEM-$CMEM

echo "Memory limit...: $GMEM MB"
echo "Current usage..: $CMEM MB"
echo "Free memory..: $FMEM MB"

Will display free memory (if you like me can't do simple math in head heh) aswell

[gerilya]

It must be VPS specific as I dont recall such entry under /proc
For dedicated server users I would suggest using sa command instead.

[thisisit3]

Thats correct, its for VPS servers only.

[thisisit3]

NEW VERSION !

i've added free memory and percentages!

[thisisit3]

Spent some more time on the script and added a few more stuff: burstable memory, requested memory

[ethix]

great script mate

made me realize i have allot of unused memory

[gerilya]

made me realize i have allot of unused memory

You might want to make sure your memory utilization remains low at all times before jumping to conclusions

BTW, here is an interesting article about monitoring server performance (should work for VPS as well)
http://www.linuxhomenetworking.com/w..._P erformance

[AlexKall]

Requested means? Heh

Get additions! Thank you!

[thisisit3]

what is "requested" or otherwise also know as "allocated" (but not "used") memory?

here is an example i've used in the past:

an application starts like:

- i've started, give me 100kb of memory
- good, now store XYZ data of 10kb size in that memory

that results in:

- 100kb in allocated (requested) memory
- 10kb in used memory

see the difference?

allocated/requested memory is not your USED memory!

[Joer.]

Hi,

Looks like an awesome script you have here. I would love to be able to use this but I am a SSH noob. I just upgraded from a shared account and haven't really learned any of the cool stuff yet.

I hate to ask for extremely easy commands but is there a way you could step by step give instructions on how to use this code?

I use the SSH terminal in Plesk and I can get to the /bin directory but I don't know how to save the code. Another step that looks confusing is the editing my bash to add the vmem as an executable....

Any help is well appreciated.


Joe R.

[thisisit3]

first check that your /root/bin is in the path by:

# cat /root/.bash_profile

PATH=$PATH:$HOME/bin
export PATH

you should be able to see $HOME/bin in the output somewhere, if its not then add the above PATH= and export lines in that file. At this point you must learn how to use a text editor like "pico" or "vi".

now make sure you have a /root/bin directory with:

mkdir /root/bin

Then change to that directory and create a file named "vmem" and copy/paste the entire code of the script in there (use your text editor again). Save it and close it, next you need to make the file executable:

chmod +x /root/bin/vmem

Thats about it, you should be able to type "vmem" at any point in the shell.

[Joer.]

Thanks for the help but I ram into some problems...

Step 1 cat /root/.bash_profile
gives me permission denied

I tried su and all the passwords I ever set for this server and none work. I am using the SST built into plesk. Is that a problem?

I know I didnt get this far but in terms of using pico.... how?

I can get to root/bin no problem I didnt have to make it. I dont know how to create a file and what extension to give it.

[thisisit3]

You are probably connected as a plain user and not as root, i'd suggest you open a ticket with support and let them explain to you whats wrong, or open a new thread since this discussion is irrelevant to the memory script.