Reinstalling boot blocks on a ZFS-only system

[Chris Ross]

  So, I've long known and it makes sense that when you're booted from a ZFS volume, you can't mess with the boot-loader.  And, I know a few months ago I had a set of commands I would use when booted from a CD that would initialize the network and copy the "release/boot" from somewhere else so that I could install bootblocks and boot-loaders from more recent code.  Sadly, I didn't _record_ those commands I was using.

  What do "people in the know" do when they want to update the bootblocks of a ZFS-boot system?  Or, have too few people followed this path so far that they can boot UFS and do it with less difficulty?

  Thanks.  Happy for any information.

                                            - Chris