I want to replace one ZFS filesystem (volume in a pool) with another ZFS filesystem (another volume in the same pool). Rebooting is okay, but I'd like to avoid single user mode.
When I try to set mountpoint=none on the old filesystem, ZFS tries to unmount it, which fails due to files being in use. Consequently, I can't set mountpoint=/data on the new filesystem due to something being mounted there. The mountpoint properties are also not written to the filesystems.
If I reboot, the old filesystem is still mounted, services will start using files on there and I can't unmount it anymore. Is there a way to write the mountpoint properties on the filesystems without actually changing anything that's mounted, and then reboot so that the new filesystem is in use when the system comes up again?