Best encoding to fit 10hours of 1080p in 30gb?
You can calculate the maximum total bit rate that would fill the storage:


30GB ≈ 30,720 MB ≈ 245,760 Mb
10 hours = 600 minutes = 36,000 seconds
245,760 / 36,000 ≈ 6.83 Mb/s


You need to encode to a video bit rate less than that maximum to account for the audio and any overhead. Plus, you probably want to leave some space free on the storage. I'd say that 5 Mb/s is probably a safe bet. From there, you should try out different codecs and settings to see what gives you the quality you want at that bit rate.