automatically starting crashplan backup when a usb harddisc is connected

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http://askubuntu.com – Using CrashPlan I've configured two backup sets: online backup in crashplan's cloud (this is running perfectly) a local backup on a usb harddisc directly connected to the local laptop. The USB drive is only connected rarly when being at home. When connecting the drive it mounts automatically. Is there a way to start the local backup whenever the usb disc connected. My guess is that using udev it should be possible to "somehow" tell crashplan to reevaluate the presence of backup location. Any ideas to do this? (HowTos)