Is there any proven efficient way on how to use Symantec Backup Exect for Windows Servers to use S3 as one of the Devices to backup to. Even if it means to use a plug-in to make it work.
I suppose you could use something like JungleDisk to expose S3 as a resource into which you could replicate a Backup Exec "Backup to Disk" folder. I really doubt that it would work well, though.
Backup Exec is primarily aimed at creating streams of backup data targeted at tape drives or disk. Backing-up data into S3 would be an application better suited for a file-for-file synchronization operation, I would think. I'm not saying that it can't be done, but I would think that you'd have a better experience performing a sychronization-style backup than a stream-style backup.