Hashing large quantities of data (as large as 400GB) can take hours to complete. Dr Bob suggested an option to turn off sleeping mode on the hashing code for when the user has such big amounts of data.
Perhaps there could be a prompt to the user, so if Retroshare recognises there is over 100GB of data or something a popup could ask 'Hashing over 100GB of data can take a long time. Would you like to turn off sleeping hash mode (this can put strain on the CPU)?' if sleeping mode is not deactivated already, if that isn't too much bother.