I run syncthing on my Synology NAS. I’ve been happy with it for a long time, but I’ve recently been prompted with an update to version 2.0.13-33 and a warning:
ATTENTION: This is a major version upgrade requiring a database migration on first launch. Please read the official release notes and be prepared for some service downtime.
I really don’t feel like messing around with reconfiguring right now… I intend to wait for a while and see what happens, but I’m curious if I should actually expect anything to break? Or is this message just a warning that it could break things?
It’s not so much a warning of things breaking (although that did happen when v2 came out back in August 2025), but a warning that this is slow. v2 is a migration to a new database engine, which means the entire database has to be rebuilt for the new engine. How long that takes depends on the amount of data you have and how powerful your hardware is, but it’s not uncommon for a migration to take several hours or even days on a slow NAS with many TBs of data.
The thing that usually breaks is if you use command line flags that haven’t been adjusted to v2. In particular, v1 supported both single dash - and double dashes -- for long-form arguments whereas v2 only supports the latter for long-form args. This tends to break old scripts.