[Borgbackup] Backup to current QNAP NAS?

[Michael Below]

Hi,

I am a longtime Debian user and amateur photographer, and now I have
acquired my first NAS and want to install a proper backup solution. The
NAS is intended for local backup and also for media storage (RAW
images, music, movies - obviously I need a separate backup strategy for
images, but this is not my current issue).

I am wondering what is currently the best way to send local backups to
a QNAP NAS (TS-451D2, Intel Celeron, 4GB RAM). There seem to be a lot
of different possibilities, thats a bit overwhelming, so I am looking
for "best practice" pointers:

1. Should I install borg on the QNAP QTS system?
a) As prepackaged by the QNAP community?
			(currently 1.1.14, https://www.qnapclub.eu/de/qpkg/488)
b) Is there a package by the borg community, for use directly on the
QNAP QTS system? 
c)  It seems possible to install it from source via Entware, but there
were some issues (https://github.com/Entware/Entware-ng/issues/851)
d) Should I install it in some kind of Container (using QNAP Container
Station)? Docker or LXC?
e) In some kind of VM (using QNAP Virtualization Station)?

2. Should I install openmediavault / Debian on the QNAP system and run
borg on that?

3. Should I run borg on the local systems, and backup to a remote file
system?
a) Backup via NFS?
b) Backup via SMB?
c) Some other file system?

4. Some completely different solution, e.g. borg talking to QNAP Hybrid
Backup Sync?


I would like to set up a low maintenance system that keeps my data
secure for some years. IMHO Debian has a good track record in this
regard, and it's a known environment, so that would argue for #2. OTOH,
I read about people booting Openmediavault permanently from a USB
stick, that seems sketchy... Plus, QNAP QTS seems to be one of the
better NAS operating systems for the media server part. So I guess borg
in a container would be the preferred solution in that context? That
seems to be less overhead than a VM? Or would you recommend using the
NAS as a"dumb" file system? Some other solution?

I am concerned about software updates - I would prefer a solution with
some kind of easy path to updates/security fixes to a "homebuilt" /
"fire and forget" solution that will become outdated unless I
continuously put in some effort. I like the way Debian handles updates.
I am not sure about QTS, or updates in a Docker image (I guess it would
have to be rebuilt periodically? Is a VM able to update itself?)

Any hints are welcome...

Cheers
Michael