Definitely for most cases, yes... but 'data' is still an issue (if you care about the data). NixOS has an interesting mechnanism for separating "package" upgrad

Definitely for most cases, yes... but 'data' is still an issue (if you care about the data). NixOS has an interesting mechnanism for separating "package" upgrades from "data" upgrades, tho, so that's a slight advantage. (They basically keep around old binaries to be able to run and back up an old database and restore it on a newer version. Straightforward file system snapshots don't really do that.) EDIT: Sorry, I feel I didn't explain this very well. The main point is: You can have multiple versions of all the software on your system, including stuff like PostgreSQL. That's actually very powerful. Another potential problem is the licensing and root-on-ZFS. Personally, I'm really looking forward to an in-upstream-kernel FS like bcachefs. (I'm actually a fan of ZFS, we use it on our servers, etc. I still feel a bit uneasy about the licensing issues and the fact that it's not in-kernel.)