I guess we all run into the problem of an endless scanning session provided by netbeans. I als run into this by using the new version 7.2.
You know that netbeans is doing something strange when your ide slows down while the load goes up. Especially when "top" displays a hugh amount of used memory, swap space and cpu time, you know it is time to say "good bye" to your opened files and use a kill to force your will.
But what to do after that?
First you can try to delete the netbeans cache.
If this did not work, you can install the plugin ScanOnDemand. If you need more information, you can take a look to stackoverflow.com
I just want to start netbeans and what happens? Nothing.
After trying it twice (via fbrun), i tried it a third time via cli/shell and there was the error "Cannot find java. Please use the --jdkhome switch.".
Next stap was to ask the preferred search engine which leads to ... well nearly no good solution. So i searched a bit wild and after a time, my mind told me to look for two reasons.
The first look was to "where the hell is my current jvm installed?" which leads me to "/usr/bin/jvm/java-*". After that i located my current netbeans.conf and take a look into it.
In the "netbeans.conf" file, my eyes founded a missconfigured line where the "netbeans_home" pointed to a non existing path. Quickly adapted it and "et voila", everything is working again.
Hint: With this configuration, you can easily switch your current used jvm!
I know it is an important feature of netbeans but sometimes it is scanning a lot, especially when you have to use a trunk and a bunch of branches, all separated as different projects.
If you want to stop auto-scanning that often (netbeans also does it after you unchecked it ;-), go to "Tools->Options->Mscellaneous->Files" and uncheck "Enable auto-scanning of sources".
Thats it! The downside of this option is, that you have to manually refresh folders by using "rightclick->Refresh Folder" in your project- or filestree.