What's the best storage strategy for many multimedia files?

Best practice is buy a tape drive with tapes, cheap and best, go for Quantum DLT, for backing up the files, you can use built in windows "ntbackup" or any third party tools like symantec or acronis.
Schedule a backup weekly normal (full) backup and daily (incremantal) backup.
Also, If you dont have much budget then go for a external Hard Drive (2 TB or more), take the backup using any backup tools.

Hope this help you to resolve your query.

With "only" 10GB per week (which require about 140Kbps of constant upload bandwidth), you can go to an online backup service.
I would suggest BackBlaze for $50 per year and unlimited backup storage....to be compared to the $1500 minimum of a tape drive and $30 per 800GB LTO-4 tape

The budget is changed to higher now.  User wants everything automatic and fast to retrieve old files which will be kept for at least 5 years.  I tends to use fast online storage and backup storage.  Any more advice please?  Thanks for the suggestions previously.

5 years at 10GB per week means managing a 3TB array...not an impressive problem.

The point would be to have them to move their old files to an "Archive" folder that you will rename ArchiveYYYY every year to allow 6 years old files to be definitively deleted.

Does your user expect you to keep every release of all files for 5 years ?
Usually, they are in charge of versionning their files...
Otherwise, we have to found another solution that automatically archive all release (like a SVN repository based replication)

Hi BigSchmuh, thanks for the input.  User expects to restore files mostly depend on timestamp.

Can you suggest them to add a timestamp to their own filename ?

Why adding timestamp into filename?  The file modification date could show the latest version.

...yes but that means your fileserver should store all saved versions of the same file...and provide users with a feature to select a specific version.

That "versionning" feature is usually available through :
-OS with a "snapshot" feature...but you can't really manage how many versions you can keep
-SVN like software used mainly for sharing source codes

Having the users agreeing on adding a different timestamp to their filenames allows to use a basic fileserver with no versionning capability.

==> Otherwise, I think the way to go is to looking for a SVN client software that allows to retrieve old release through a contextual Explorer menu. I suggest you to have a close look at:
- SmartSVN : http://www.syntevo.com/smartsvn/index.html
- TortoiseSVN : http://tortoisesvn.tigris.org/

What if user doesn't have source code programming, will the SVN s/w be good for her too?

Thanks a lot, BigSchmuh!