"Reallocated sector count has increased" email notification

Thanks alot for the explanation what the error I am seeing is. Am I safe assume the data is successfully moved from the damaged sector to the undamaged location such that as on subsequent back ups, I will not have LOST any data (like during the reallocation)?

BTW, ballpark-wise, how much data are we talking about when the 18 sectors reallocated occurred?

Since this disk is listed on the ReadyNAS compatible list, I assume someone around here knows (at least general) the expected 'tolerance' question you recommend I ask Seagate. I will wait a week or so to see if someone can post it here since I am preparing for an out-of-town trip starting tomorrow for a week and do not have much time to spend on this at the moment. I will try to sneak in a call to Seagate this week, if possible.