i have a Dualboot System, macOS Sierra & Ubuntu 16.10. Is there best practice how to auto export/import pool when booting into other OS and vice versa?
But you can also make OSX have the same systemid as your Ubuntu, I believe ZFS will only set sysctl's "kern.hostid" if it is zero, so a user can set it to the same ID as Ubunto, before ZFS is loaded, if they wanted to. But generally that is more hassle than it is worth.