[ Thanks to Ahmed Kamal for this
link. ]
“I have also used the command “apt-clone” to list the
currently available boot environments. Basically, using ZFS
snapshots the whole machine state is snapshot’ed resulting in a
instantly bootable environment. Currently we only have the default
environment “rootfs-nmu-000”. Now I am going to use apt-clone to
“dist-upgrade” the whole system. If this is new to you (who has
never seen Ubuntu 🙂 it basically means you’re upgrading the whole
system to the latest tasty bits…“Note that the “A” and “C” in the output mean “Active” and
“Current”. Great, now creating instant bootable system snapshots
like that is so useful that it does not relate to software
installations only. Say you’re running some third party closed
source installation application and you’re not really sure what’s
it going to do to your system. Or if the new clueless administrator
needs to install something to the server but you think he’s
probably going to destroy it! In such situations, it’s very helpful
to manually create a system snapshot. So, let’s do just that to
create the environment 002 and let’s activate it.”