Drew Webber (mcdruid) is a UK Drupal developer, PHP programmer and linux sysadmin. This is his website.
I was struggling with jmeter running out of memory when doing some load testing, and almost all of the instructions I found about how to increase the java heap size and give jmeter more memory were for windows, and talked about editing a jmeter.bat file which I do not have on my ubuntu (10.04 LTS) machine.
Other posts suggested setting various environment variables (e.g. HEAP or JVM_ARGS), but these didn't seem to work for me.
I finally found the correct incantation - or at least one that works. You could edit the jmeter script at /usr/bin/jmeter (or wherever yours lives), but I prefer to create a little launcher script so that I don't lose my changes with a package update.
So here's the launcher script I'm using:
#!/bin/bash heap_size='1536m' JAVA_CMD="java -Xms$heap_size -Xmx$heap_size" jmeter
I suppose you could set JAVA_CMD elsewhere, but you may not want it to get picked up by whatever other java apps you use.
I would imagine the same approach would be valid in other flavours of linux too.
Share and enjoy.