zfs_enable vs zfs_load in loader.conf (but neither works)

[J David]

On Mon, Sep 9, 2013 at 1:38 PM, Adam Nowacki <nowakpl at platinum.linux.pl> wrote:
> zfs set mountpoint=legacy data/root
> together with
> zpool set bootfs=data/root data

This does appear to work, thanks.  So the key steps seem to be:

1) zfs_load="YES" in loader.conf
2) zfs_enable="YES" in rc.conf
3) Set bootfs=data/root in the zpool.
4) Set mountpoint=legacy on the root fs

Using mountpoint=legacy seems a little conceptually challenged,
especially given that the description of a legacy mount is:

"If a file system's mount point is set to legacy, ZFS makes no attempt
to manage the file system, and the administrator is responsible for
mounting and unmounting the file system."

Is this bending things to claim setting bootfs is adequate example of
the administrator's responsibility to mount the file system?  (Even
though that is clearly also part of ZFS.)

How does mountpoint=legacy interact with importing the pool on another
system, or from a LiveCD, with " -o altroot=/mnt " ?  (A case where
mountpoint=/ works perfectly.)

And, finally, what would have to change to support a ZFS root
filesystem set as mountpoint=/ instead of mountpoint=legacy ?

Thanks!