Version: unspecified (using KDE 4.4.4) OS: Linux When you ask dolphin to enable thumbnail view, kio_thumbnail starts up, however when you turn the thumbnails off, the process still persists, it's expected to be killed. Reproducible: Always
The thumbnail process is implemented as a KIO process and like every other kioslave it is managed by KDE IO schedeuler. When kioslaves finish their work, they are kept for a given duration, in case they need to be resued, before they are killed after a certain duration (~ 3 mins). Simply enabling and disabling the preview button in dolphin will not kill these processes.