Hello,
I’m using syncthing (SynoCommunity version 1.23.4-29) on Synology DS213 NAS (DSM software 6.2.4-25556 Update 7), and I’m really pleased. Except that hibernation (disk suspend) wasn’t working anymore.
I just want to let you know that I found the culprit: in syncthing log, I could see a lot of messages like “Accepting connection: read udp [::]:22000: recvmmsg: function not implemented”, “QUIC listener ([::]:22000) shutting down” and “QUIC listener ([::]:22000) starting”. I think it triggered frequent journaling or something like that preventing hibernation.
In syncthing connections configuration, I changed “Listen Addresses” to “tcp://0.0.0.0:22000, dynamic+https://relays.syncthing.net/endpoint” instead of “default” to disable UDP QUIC protocol, and now my DS213 is able to hibernate.
I’m not sure this advice applies to all Synology NAS, maybe only on some models or some DSM software version.