Take them with you, put them back
Nexview has always put a copy aside before rebuilding its database — but that copy sat in the same directory as the database. Lose the volume and it goes too. Since 0.22 you make one on demand, download it, and restore it: into the running installation, or right in the setup wizard of a fresh one.
An encrypted ZIP — and why it has to be one
The archive holds the database, the profile pictures and the key file secret.key. The key has to come along: your credentials for Radarr, Sonarr, TMDB and the mail server are encrypted with it, and without it they cannot be read again.
That is exactly why the archive needs a password — and exactly why it is a plain AES ZIP rather than a format of our own. You can open it with 7-Zip or your file manager. You do not depend on Nexview running to get at your own data.
Caches are stripped out. By far the largest part of the database is stored TMDB answers and the library comparison — both of which Nexview fetches again by itself. That is why a backup is a few megabytes rather than a few hundred.
Daily, weekly or monthly
Weekly out of the box. Switchable to daily, monthly, or off entirely. Automatic backups are marked as such so you can tell them from the ones you made yourself — and a manual one also carries whatever note you gave it.
How many are kept is up to you; five by default. Whether one is due is worked out from the dates of the files that exist, not from a stored timestamp — so a container that was switched off over the appointment catches up at the next start.
Including on a fresh installation
An empty installation asks first: start fresh, or restore from a backup? Anyone moving house or coming back from an outage no longer has to walk the whole wizard and then rebuild everything by hand.
It checks first whether the backup even fits. Nexview can only migrate its database forward — an older backup is pulled up cleanly at start, a newer one is refused. It would come from a version whose tables the running one does not know, and what it does not know, it reads wrongly or not at all. The refusal names the reason rather than just saying “not compatible”.
Before restoring, Nexview writes a safety copy of the current state. And afterwards every sign-in everywhere is ended — including your own. That is deliberate: the accounts in the backup may not be the ones from a minute ago.
What a backup is not
It sits in Nexview's data directory. As long as it sits there it shares the fate of the database — a backup you have not downloaded does not protect you against losing the volume. The download button is the actual point of the whole feature.
And it backs up Nexview, not your media library. Movies and shows live where Radarr and Sonarr put them; for those you still need whatever you already use.