zfs VS archiso-zfs

https://openzfsonosx.org is a great starting place for general ZFS on Mac stuff.

I am imaging the following simple situation. I am using open ZFS on macOS (OpenZFS on OS X), and I have created a zpool with a single external USB drive. What command should I run when the drive is accidentally disconnected without properly exporting the pool?

This is completely wrong. ZFS works very well via O3X [0]. I ran my home folder off of ZFS on various Mac Pros for ~11 years. ZFS works well in Linux and FreeBSD as well.

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0: https://openzfsonosx.org/

This might be able to read the drive https://openzfsonosx.org/ But I don't know if Time Machine will jive with it.

After dabbling with early stuff from the sadly scrapped Apple effort, I started my full time Mac ZFS journey in 2011 with the then Z-410, which then became ZEVO which was 10.8 only, and then staying on that (and in turn 10.8 doho) on a Mac Pro 3,1 for a solid 4 years or so. I was really sad when that effort didn't pan out and the company got acquired and then the whole deal was killed, but O3X revived the torch and I moved directly onto that. I've carried my pool forward continuously the whole way, with snapshots and everything, all data scrubbed and known good with no more data rot. It's a damn shame events (software patents) conspired to keep that from becoming a universal native fs, but it's still a wonderful thing and Lundman's amazing consistent efforts have been fantastic. The main site at https://openzfsonosx.org/ has decently active forums for something niche.

Without Apple on board or a much bigger effort ZFS on the Mac will probably always have some real limitations particularly with the GUI. For one of my desktop systems I've migrated to running my home and data folders as HFS or APFS formatted iSCSI targets, so it's still on ZFS underneath but appears native to macOS (and that also means that the effective death of towers isn't a limit on storage). But this remains an incredible project IMO.

Also for anyone who wants some limited GUI interaction capability, there is a small project called ZetaWatch [0] which will put some ZFS control into a menubar widget.

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0: https://github.com/cbreak-black/ZetaWatch/

OpenZFS is available for MacOS and it's about as rock solid as you get in a file system. As a bonus, if you someday need to migrate the dataset to a server, you'll be able to import the zfs pool pretty easily.

Check out https://openzfsonosx.org/

Site ZFS on OSX seems down for the last few days...

>such as ZFS

FWIW, ZFS has actually been available on macOS for a long time in various iterations (MacZFS, Z-410/ZEVO, and now OpenZFS [0]). I ran it for around 11 years on a number of systems with almost all of my data on it (home folder, applications, /opt for MacPorts etc) and it was a tank. Fun project and well worth checking out. I'll always regret the various factors that meant Apple didn't adopt it as their native FS.

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0: https://openzfsonosx.org/

DKMS is the best option if you really want to keep up with Arch updates and if you're experienced with Linux (for instance you know how to fix your system from the archiso if needed -- for ZFS you'll need to manually load the zfs module from the archiso; this script is very helpful).

Make an EFI boot partition of maybe 200MB using your favorite distro iso and make a zpool on a second partition of the remaining space followed by a single dataset on that zpool named root at the minimum with normalization=formD, compression=lz4 or zstd and optional encryption flags and install your rootfs to that. I've found this process is easiest using the Archlinux ISO and this github project to get zfs in the archiso environment.

The script available there: https://github.com/eoli3n/archiso-zfs makes it extremely easy to add ZFS support to any Arch ISO after it has booted. You can copy any standard ISO to a USB drive, boot off it, then run `curl -s https://raw.githubusercontent.com/eoli3n/archiso-zfs/master/... | bash` and you'll have ZFS support in a few seconds, without having anything to worry about.

With Arch there is an easy way to get the iso to read ZFS with a simple script, it is a bit of a no no unless you verify the script before using it. https://github.com/eoli3n/archiso-zfs

My own experience is with ZFS, first on Arch Linux (using the excellent https://github.com/eoli3n/archiso-zfs). I learned a lot doing that and modifying the scripts to my liking.

You can load zfs modules in the archiso with: https://github.com/eoli3n/archiso-zfs

Because zfs isn't part of the mainline kernel -- you need to add the appropriate packages during the install process -- meaning you need to either boot from a standard Arch ISO install disk and then download the packages as explained here: https://github.com/eoli3n/archiso-zfs or you need to make a custom arch ISO where you add the zfs packages. https://wiki.archlinux.org/title/ZFS#Create_an_Archiso_image_with_ZFS_support. The only issue with creating the custom ArchISO -- you need an actual basic arch installation somewhere to create the disk -- so basically you need a standard Arch installation to create a custom install disk whereby you can install an Arch zfs installation. Here are other good tutorials for this: https://ramsdenj.com/2016/06/23/arch-linux-on-zfs-part-1-embed-zfs-in-archiso.html

Both ZFS updates and pacman breaking are rare enough that I forgot that would happen. Though using this rescue system would work, there's also a group that maintains a script to grab the correct ZFS module for a running archiso, might come in handy for you.

https://github.com/eoli3n/archiso-zfs

You're having a problem due to archiso not updating every time the kernel updates, though you could fix this issue there's also just an easier way. The archzfs repo group has made a tool to grab the correct zfs module for the running kernel, see https://github.com/eoli3n/archiso-zfs