Now change to DSA is coming up and keeping settings is not recommended.
I have some questions in advance before facing bigger problems and ending up in annoying reconfiguration.
Can i still use the above-mentioned instruction or do i run into the same problems as with keeping settings in the "normal" upgrade option?
what is lost by upgrading without keeping settings?
a) Changing IP from default to 192.168.0.1
b) Static leases
c) USB support
d) mount points
e) networkshares
f) Configuration of Dynamic DNS
g) Configuration of wireguard: keys, etc
Can you recommend a way to avoid re-configuring? Even better, is there a step by step instruction you could share.
WRT1900ACS --> mvebu, which in turn means the swconfig --> DSA migration happens between 19.07.x and 21.02.x for this device.
Follow the advice and reconfigure from scratch (only using your old configuration as loose reference), the networking syntax and semantics will be completely different, keeping settings (or restoring old backups) would result in a guaranteed (soft-)brick.
You need to start the config from scratch.
For the packages you need, and default ip adress, you may build your own image with Image Builder.
This looks scary, but you'll get it done, it's easy to rebuild your own image for each upgrade without to have to reinstall the specific packages. Config can also be preserved, excepted for this transition from 19 to 21.x version.
Thanks for your reply. Unfortunately it seems to be some amount of work and at least some risk for transient loss of function... I will order a second (backup) router, to avoid trouble with my family ;-).
Regarding image builder. When i have Managed to setting Up the first router with 21.02. my intention is to Clone everything and Set Up the second (Back Up) Router exactly the Same way. Is There an Option to "Clone" everything (package config etc) build an Image and transfere it to the second Router. Aim is to have two identical router for Back Up purpose.
After the config from scratch, which took a while here (because of banip, wireguard, firewall rules, stubby, static dhcp leases), 21.02.1 runs very stable ...
Did spend/waste some time yesterday evening, now wireguard and ddns run without errors. Did Have some trouble with USB support which ist not solved yet.