Hi sedatdrkn
What will happen is this - sometime before the 5 years is up, you should be contacted (or your organisation) by Veritas/partner and asked whether you wish to continue to subscribe to NetBackup for a further period (you will have the option of the duration). If you choose at that stage to not continue the subscription, then as per the product use rights agreement, if You are no longer licensed to use the Licensed Software under a current subscription or term-based license, then You may use the Licensed Software without a current license for twelve (12) months following expiration of the subscription, for the sole purpose of restoring data backed up by the Licensed Software prior to expiration of the subscription. Any such use shall be consistent with the terms of the License Agreement and this Document. No maintenance/support will be provided for the Licensed Software for such restoration use. (https://www.veritas.com/content/dam/Veritas/docs/eulas/NetBackup_v10_1_1_PUR_15Dec2022.pdf)
As for whether it will continue to operate, that far out I am unable to comment. A lot I believe will depend on the NetBackup version you upgrade to along the way and how licensing is changed (if at all) with the newer versions.
If you remain on a current version for 5 years (not really a good idea), then after 5 years I believe NetBackup will continue to operate as it does now, but if you don't maintain support and continue to use the software for backup, then I believe you would be breaching the license agreement for the software.
Note that all my responses are my opinion only based on what I understand. Your Veritas account team (or Veritas partner) can provide a definitive answer for you.
Cheers
David
Cheers
David