After the update to 14.04 Kubuntu I did notice an executable running constantly using up to 95% of my CPU time that I had never noticed before. The executable was baloo_file. Not knowing anything about it, I found out on the internets that this is the new file indexer coming with KDE 4.13 which is replacing nepomuk. First thing I disabled in older KDE installations was nepomuk. I found it not useful, a resource hog slowing down my system to a crawl, and a generator of gigabytes of index files clogging my hard drive. As clever as indexing for better and faster searches might be, I never use it anyways, so I don't want it. In KDE releases < 4.13 you could turn Nepomuk simply off in the System Settings.
Due to the KDE developers you cannot disable baloo at all. You can suspend it (happens on low battery for laptops...), but the suspend command I found failed on my system with an error:
Them KDE devs recommend to add your $HOME directory to the list of directories not being indexed by baloo. I try that and added /home/ and my $HOME directory to the list of directories not getting indexed. Unfortunately it would not stop the darn thing. After only one day with KDE 4.13 I had accumulated 1.8 GB of index files in ~/.local/share/baloo.
qdbus org.kde.baloo.file /indexer suspend
So here is what I did to get rid of it:
1. removed all contents in ~/.local/share/baloo
2. made the directory unwritable for anyone:
rm -rf ~/.local/share/baloo
3. You can probably stop there, but might end up with crashed executables. So for good measure I created a little script in my $HOME/bin directory which I made executable and did add it to the list of scripts executed on KDE startup:
chmod ugo-w ~/.local/share/baloo
killall -9 baloo_file_cleaner
killall -9 baloo_file
killall -9 baloo_file_extr
rm -rf ~/.local/share/baloo/*
So far no baloo services and no files in ~/.local/share/baloo.