preserve_* options and luks partitions

[Thomas Lange]

>>>>> On Thu, 11 Mar 2021 22:43:31 +1300, Andrew Ruthven <andrew at etc.gen.nz> said:

    > Is the reason that setup-storage can't just leave these volumes alone
    > if they already exist?
Hi Andrew,

the setup-storage tool was written long time ago mainly by a guy
who is not active in FAI any more. Another guy added btrfs support and
I have some minor knowledge about how this tool works. But I do not
know much about all the crypt stuff and why is was decided not to
support crypt configs. Maybe noone though that people will need this.

Preserving in setup-storage is not just "leave this untouched" but may
include much more logic behind the scene. For example,
when setup-storage preserves a physical partition, it needs to know the
start and end sector of it because it will not leave the partitioning
for this disk untouched, but it writes a new partitioning (because
other partitions may change) but preserves the start and end sector of
the physical partition which is marked as preserve.

This may be a reason why it was decided not to support crypt setups.
Maybe you will find some explanation in the git logs.

-- 
viele Grüße Thomas