I have an imac and I have had a problems with accidentally deleting old backups and it takes forever for trash to clean it and not always successful. My imac is 1TB and i have an external 1.5 TB so there is plenty of room unless time machine just adds another instead of overwriting old backups or simply not deleting. Can anyone suggests better way I don't wish to have to go through trying to empty trash and taking forever. Onyx keeps crashing, I have 10.9.1 Maverick OSX, if you could do a step by step to avoid all this nightmare I would be grateful.