Hello Librado and Welcome to Veeam Forums!
Does veeam backup have a retention period of 7 years on backups written to tapes?
If I am not mistaken, the UI is currently limited with a value of 999 days but for specifically for long-term retention we have a special Protect option, which is identical to the hardware write protection switch inside the tape media. New protection mechanism could be used for single media or for the whole scope of tape media during export to the logical media vault.
does it keeps a media database of which we can track/identify which tapes is used for the month end backup to tapes should we need it for file restores?
Sure, VBR got a media view and file catalogue view, with both of these you can easily identify where the specific data resides and what tape media could be overwritten according to your retention.
do we need to restore an entire 11TB file to restore a single file?
VBR has two types of tape jobs – file to tape and backup to tape. In case of file to tape, where the source is raw files on your machines you can restore a single file from the scope of backed up to tape files. However, if you use the backup to tape, the entire backup restore is required, for example to performed a file level restore from a backuped VM.
Here is a link to the Veeam B&R v8 user guide where all the functionality is documented:Veeam Backup & Replication v8 User Guide
In addition, we have an online help center over here: Veeam Backup & Replication Help Center
Let me know if you have any questions or need any assistance,