Which macOS folders are safe to put on ZFS?
Posted: Thu May 06, 2021 9:53 pm
Boot on ZFS seems to be a no-go right now, at least on Catalina on my 2015 MacBook Pro. That leads me to wonder, how much of the macOS system can I put on ZFS, assuming that I maintain the macOS install on APFS? In particular, I am wondering how it works with upgrades.
Here are the root folders, and some hunches:
- /Applications - Maybe? I would love to ZFS this folder. My main concern is regarding macOS updates. If macOS updates e.g. Terminal.app when the ZFS pool isn't mounted, then the next time I mount /Applications I won't actually be getting the macOS updated version.
- /Library - no idea. Possibly the same as /Applications. If macOS reads / writes from it before mounting ZFS, that could cause problems.
- /System - I assume that at least a big chunk of this can't be moved to ZFS.
- /Users - certainly. It's probably a good idea to create an `admin` user on the APFS volume so there's at least one login that isn't dependent on ZFS
Have other people moved /Applications and /Library on to ZFS (and kept the APFS macOS install)? If so, have you run into any problems - and how does it work with Software Update?
Here are the root folders, and some hunches:
- /Applications - Maybe? I would love to ZFS this folder. My main concern is regarding macOS updates. If macOS updates e.g. Terminal.app when the ZFS pool isn't mounted, then the next time I mount /Applications I won't actually be getting the macOS updated version.
- /Library - no idea. Possibly the same as /Applications. If macOS reads / writes from it before mounting ZFS, that could cause problems.
- /System - I assume that at least a big chunk of this can't be moved to ZFS.
- /Users - certainly. It's probably a good idea to create an `admin` user on the APFS volume so there's at least one login that isn't dependent on ZFS
Have other people moved /Applications and /Library on to ZFS (and kept the APFS macOS install)? If so, have you run into any problems - and how does it work with Software Update?