Hello,

How can I achieve this form of backup?
I want to drop the Apple subscriptions for iCloud backup and do it locally. I saw a tutorial about Nextcloud and how to set it up. But I am wondering, how can I back up the photos/videos/files to have an extra backup?
Can I set up another disk or folder just to have the same backup synchronized elsewhere? Or do I need another server?

I was thinking of making another folder on the same server and synchronizing it with the primary one.

It depends on what you want to achieve.

You can replace iCloud to backup photos with immich or nextcloud but you will loose some functionnalities.

Apple photos works with icloud; it manages pretty well what is stored on the phone and what is in the cloud if your photos library exceeds your phone capacity.

If you want to have an extra backup you can use a docker like icloud drive sync (don't remember the exact name) to download your icloud photos on your server.

For now i still have icloud but i have my phone upload all photos to my nextcloud as backup and i also download photos from icloud to my server and mount the resulting folder in immich as external library.

I want to backup my documents and photos/videos.
I wanted to leave the iCloud subscription, but I will see more information about what app you did provide.
I was thinking about a fail over of my documents and photo/videos, to be in another folder. A backup to backup.

Leaving the transition apart it seems to me that using idevices without icloud is very difficult as it is deeply integrated in ios. it's used for documents, photos, backup and sync of apps, backup of iphones

It's feasible but if your device capacity is too small for holding your documents and photos it will not be convenient as you'll have to manually manage which doc has to be available offline.

I do it for docs using nextcloud. The downside is managing offline availability. I also use calendar through a caldav account on my nextcloud and so on for contacts with a card dav account.

For the photos i use immich with an external library and no upload of photos from the phone (it's made by a docker ). If i should not use photos anymore i could make my phone upload photos to immich and delete them from photos. Of course you have to manage the initial upload of your existing library. I don't know if you can retrieve albums that way.

Of course you have to verify that other sync you may have with icloud fit in the basic account.

And finally for the backup you have to use finder or itunes on a pc. I don't know a replacement for icloud wireless backup.

Nextcloud + Immich + iMazing (paid software) and you'd have to run in a VM

Best you're gonna get outside apples walled garden