Dear Debian maintainers,
first I like to thank you for the terrific job you do, Debian evolved to
such a great system!
Upgrading my computers to Debian bookworm I encountered some issues and
therefore I would like to make some suggestions for further development.
The btrfs filesystem comes with features like cow, snapshots and dynamic
distribution of storage space between partitions (subvolumes). These
qualities make it perfectly suitable to install the operating system
onto it. Despite alot of articles on the Internet BTRFS today is very
stable! I tried to crash it often in the middle of large transactions by
turning power off and never had any problems to just restart and keep on
doing.
I usually install Debian onto two partitions on small computers like
notebooks. One partition for root (/) and another for user data (/home)
besides the partitions the hardware needs (EFI). This way I can do
backups from /etc to /home and at any time am able to format the root
partition, reinstall the computer and am back to a fresh system without
loosing any data, in case something awful happens.
The problem always was, that there was alot of disk space wasted because
these partitions both needed to be large enough to handle further
development. (always guessed wrong)
Btrfs subvolumes @root and @home on one single physical partition would
solve this, besides ssd support and snapshots, in a perfect manner.
The issue with bookworm installer: It is able to install those two
subvolumes, but in case of a reinstall it does not support to just
format (or better clear) the @root subvolume for installation and leave
the @home subvolume untouched. The installer is only able to format the
physical partition and destroying all user data.
My suggestion: Make the installer support BTRFS subvolumes which are on
an existing disk like it does for physical partitions.
Even better also support discoverable partitions like described at
https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/
and have a feature to just reinstall the operating system and not touch
the data.
I am sure you are thinking of something like this already, then take
this as another vote.
Sincerely, Richard
