How to install a VPN server on NSA325-v2

Mijzelf

When everything works now there is not much point in upgrading to Debian. Theoretically you could get a more performant VPN (Wireguard is less CPU intensive than OpenVPN or 'SOCKS over ssh' (The latter 2 use the same encryption)), but as long as you only get 200kB/sec from the available 1MB/sec, there is some other bottle neck than the CPU.

Installation of Debian doesn't necessarily kill your data, but of course it's easy to do it by mistake. When you are really concerned about that, you should be aware that you should have a backup. Your NAS is not a magical box which keeps your data safe for eternity, but it's a piece of electronics with a mechanical disk, which will fail. some day.