Sudden crash, possibly Volume Replication error?

Hi,

This weekend we experienced an open-e production crash. We couldn't log on to the web interface and als all NFS volumes were unavailable to our VMs.
After performing a hard reboot, all came back online and works ok.

We have several iSCSI targets on this Open-e too and are Volume Replicating those to another Open-E on the network. Around the crash we got these errors on the crashed DSS-machine:

Volume Replication:
Device lv0001: Connection (from SyncTarget to WFConnection).
Mode local/remote (from Secondary/Primary to Secondary/Unknown).
DataStatus local/remote (from Inconsistent/Consistent to Consistent/DUnknown).

I suppose these are either what caused the crash or what happened after the crash?

How can we find out what was the exact cause?

Thanks in advance

Check the dmesg.2 logs and the critical error logs as well, if possible post them here so we can see what might be happening.