[GTALUG] Encrypted backups and sync

[D. Hugh Redelmeier]

| From: Alex Volkov <avolkov at gmail.com>

| So, I have several laptops and a desktop that I would like to back up and
| keep in sync.

Sorry that I don't have time right now to carefully read your list of
requirements.  But let me throw a thought.

If you go to the trouble of encrypting the filesystem on your
notebooks, it would be great to back it up as-encrypted.  That way
there is only one route to the break the encryption.  (There might
otherwise be two or three.)

Backing up a whole filesystem seems expensive: there are a lot of
empty blocks.

The first time, it is expensive.  You've got to copy all those blocks.

If you use rsync for subsequent backups, I think that it will only
transmit the changed blocks.  That should be affordable.  For safety,
it may be important that the filesystem be read-only while the rsync
is running (that might be awkward).

The only way of recovering is to recreate the raw filesystem and then
use LUKS to get at it.  Is this good enough?

Note: I've never tried this.  It might be a dumb idea.