On Mon, Nov 2, 2020 at 5:45 AM Patrick O'Callaghan
<pocallaghan(a)gmail.com> wrote:
I'd normally upgrade, but my /dev/sda uses LVM to handle root, /home
etc. and from what I read this cannot be converted directly to BTRFS,
which I'm interested in using.
ext4 can be converted to Btrfs but I can't strongly recommend it
because you're not going to get the same layout as a default
installation. The conversion won't remove LVM, and it won't add the
subvolume layout we're using where "home" and "root" subvolumes
are
assigned to /home and / mountpoints respectively.
What would be the best way to approach this?:
1) Do a system upgrade and then convert to BTRFS by backing everything
up and restoring it (I'd need guidance on how to do this).
2) Do a complete system install and then restore from backups.
I'm guessing that (2) is the simplest answer, but I'd appreciate any
comments, especially from people who have actually done either of
these.
Top choice:
Backup /home. Optionally /etc. And hand it over to the installer for
complete wipe and clean install. From scratch setup. And after going
through initial setup, restore /home (specifically restore the
contents of ~/ for each user). Probably the most straightforward.
Second choice:
Esoteric but a rather neat trick, is btrfs conversion, snapshot root
and home. And use Btrfs send/receive to populate a new Btrfs file
system with those snapshots. The conversion to Btrfs is merely a means
to being able to use send/receive to replicate them. You get to keep
your customizations without a clean install, but you do get the
subvolume layout of a clean install. It is a bit partition-ninja. And
there are post steps like all the bootloader stuff. It really depends
on how comfortable you are with a rather low level process of
migrating the data, almost inevitably messing it up, and working
through the screwups. I've done quite a few of these and manage to
screw it up somehow, and have to backtrack but I also don't panic
easily, not least of which is a bunch of backups. So no matter how
badly I mess it up I know I'm not losing things I care about.
--
Chris Murphy