I'm inclined to agree with the later comments. As nice as it would be to provide a solution for them, I don't think it would be cost effective.
Perhaps offer them guidance and support on backing up their work, as well as finding appropriate tools for doing so?
I know it sounds like you're holding their hands a lot, but some people just aren't tech savvy.
The problem with this is it would cause more problems than it would solve. I would end up spending much of my time helping people back up work etc (A lot of user may not be tech savy at all, so I need to make it as fool proof as possible.. Also if we encouraged students to all get external hard-drives, they are likely to start working off them. This is ok for audio and still imagery, but if they did it with video work then it is going to cause me a world of grief. A combination of different makes, models, connections and file systems would again lead to my time being taken up with fault finding. I don't mind students backing up for their own peace of mind or to recover work whic htye themselves have messed up, but relying on them in the case of a major failure may not be the best thing.
I know people talk about fire / flood damage but at the end of the day if either happened I'm sure there would be a lot more at stake than some student videos gone missing, such as the uni / school being gone...
I can't see how you'd ever get it backed up if the files are changing that often unless you replicate constantly...
It's not just major fire or floods that would be the issue though. Water damage (And with the amount of luck I gave had with leaks and water damage recently, this is one that worries me), electrical problems, virus etc may all lead to a major data loss without wiping out the whole school.
The backup wouldn't need to be kept 100% up to date, but being able to recover say 1 week back should be sufficient and would save a lot of work.
I really cant see the point of the install here of a 50Tb SAN. If you are saying that all the students have local storage to work on, and that you are thinking of making it their issue to secure their data in the event of a failure, what is the point in a centrally managed storage soloution, which wont be managed properly.
With that amount of data, either it gets managed properly with scheduled backup windows and proper management buy in, or dont do it at all.
The students won't have local storage to work on. All of the students need to be able to access any of the computers and carry on their work. The options I see for this are; External hardrives, and as I mentioned above if the students provide their own this will cause more problems than it is worth due to the mix of different makes, models, connections and file systems. So we could provide them, but take 1000 students and all give them all a drive and you have just spend as much as or more than a decent SAN. Or implement a SAN, which will be managed in terms of user quotas, and hopefully backed up if I get my way.
Sorry to butt in .. i'm new here.
Will the students be storing and working off directly on the SAN or will they be working on their local disk and then they would need to do the backup themselves.
If they will be working directly on the SAN, with the students reading/writing large HD files - are you sure that the SAN will cope? That is from a bandwidth perspective and also from the NAS perspective ( that is the OS firmware on the NAS ).
They will be working directly off the SAN. Yeah the bandwidth and access times etc have all been carefully calculated and the SAN will be more than able to cope. We are aiming to get enough bandwidth from the SAN to be able to saturate Gigabit Ethernet for 26 machines at the same time. This is enough to provide 5 streams of Pro-res 422 for each machine at the same time.
). Have a much smaller NAS (Drobo FS) and have the users working locally but then backing up directly to it. I am a PC house so I cannot use Apple's Time Machine but I am using the PC equivalent called Altaro Oops!Backup (
and still room for another 20 disks! 
