My Debian 8.9 DRBD 8.4.3 setup somehow has got into a state where the two nodes cannot connect over the network any more. They should replicate a single resource
r1, but immediately after
drbdadm down r1; drbadm up r1 on both nodes their
/proc/drbd describe the situation as follows:
on 1st node (Connection State is either
1: cs:WFConnection ro:Primary/Unknown ds:UpToDate/DUnknown C r----- ns:0 nr:0 dw:0 dr:912 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:20
on 2nd node:
1: cs:StandAlone ro:Secondary/Unknown ds:UpToDate/DUnknown r----- ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:48
The two nodes can ping each other over the IP addresses cited in
netstat shows that both are listening on the cited port.
How can I (further diagnose and) get out of this situation so that the two nodes can become Connected and replicate over DRBD again?
BTW, on a higher level of abstraction this problem currently manifests itself by
systemctl start drbd never exiting, apparently because it gets stuck in
drbdadm wait-connect all (as suggested by