What do you use to backup your system?

[Flyboy]

We all know the 3-2-1 of keeping any electronic files, its probably why most of us are running HexOs on a NAS. Three copies of your data, Two different storage formats and at least one offsite. What applications are good for backing up the NAS? Also, what applications do you use to backup important PC files to your NAS?

I am still new to owning and running a NAS, and so far all I have is Plex and Immich, but I am curious what other applications people like and are must haves, especially if its dealing with backups for your data.

[OrionArkk]

I'm a slowly "test the waters guy" kinda guy so I'll be having a smaller NAS of 16tb. I have an external disk for 16tb will do a backup once a month. Easy, simple. I find that works best. 
 

I've heard backblaze has a backup for NAS, but it's not inexpensive. 

[Mobius]

i don't have a good answer for cloud backup
but one thing you want to keep in mind is egress price (aka price it'll cost to redownload your data)
some services have large fees for that.