• takeda@lemmy.world
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      11 months ago

      BTRFS and ZFS filesystems offer lightweight snapshots. So you can save the state of the filesystem and restore it. It is often integrated with the package manager and a snapshot is involved before you make change.

      NixOS works differently. You have a configuration file, and each time you make change to it NixOS rebuilds itself to its specification from scratch (you might assume it would be a lengthy process, but because of caching only things that are rebuilt are things that you are changing).

      This means that things like for example squeezing from KDE to Gnome or X11 to Wayland aren’t scary to try and you can easily revert things back, your home directory won’t be touched.

      Also those things aren’t exclusive you can use BTRFS and ZFS on NixOS to and enjoy their benefits.

      • 0x4E4F@sh.itjust.works
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        11 months ago

        You can also exclude any directory you like from snapshots, including home, that’s not a problem.

        • takeda@lemmy.world
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          11 months ago

          Yeah, you can if you plan well enough (typically. What I’m trying to illustrate is that this works by taking a snapshot of the disk in time. It’s like keeping a working copy of your system on your disk to be able to revert to.

          While with NixOS you work with a “recipe” how your system is supposed to be configured. It is much lighter. It is declarative, you change the recipe and get what you described, you change configuration and all packages which you did not mention and are not used by anything are gone. If you update your system you can use the same configuration on it

          The thing is that using can still get BTRFS or ZFS and use it to have snapshots too (for example your home directory)