Buggy. Do not use unless you're feeling adventurous and like supporting your own systems.
Install Debian on ZFS, with sysvinit, optionally encrypted. You can optionally use legacy mountpoints and manage mounts with fstab, and that's Just Fine.
20220810: Added installer-vm, a cut-down version fit for VMs that uses LVM instead of ZFS and doesn't use encryption or mirroring at all, the notion being that you're inheriting these from the hypervisor.
Parts of this have doubtless bitrotted - I don't use native encryption much, for instance. Worked last time I tried it.
This used to support Devuan and Ubuntu installs as well, and can trivially support those with some minor modifications.
*** This will destroy your disk. By design. Don't use it. ***
Note that pre-existing MD-RAID metadata will often resurrect itself spontaneously, so in my actual usage, I often stop between steps, mdadm --stop --scan, and mdadm --zero-superblock the right places. Automating this has been a merry chase so I've yanked that out for this initial posting.
Note that this requires that you have a local APT repository with ZFS packages. I follow this guide:
I use a metapackage that depends on the most recent two ZFS kmod packages I've created and that conflicts with anything newer than a kernel for which I've already built ZFS. Each kmod package is specific to a kernel, and depends on the ZFS userland packages and the requisite kernel bits. An example umbrella metapackage and an example single-kernel kmod metapackage are included in this repository.
This is intended to run off from the Debian standard live media. It's historically also run from Ubuntu live images. It might run from Hrmph. It can cross-install.
Note that my funny try/catch trick is generally useful and I need to use it everywhere. Note also that I need to make this way more granular, with each option having its own checkpoint. I lump some things together now that should be distinct. But I want to get this out rather than just shoving the version de jeur into pastebins every few months for years now.