I had one of my OSDs crash yesterday. I'm using ceph version 0.56.3 (6eb7e15a4783b122e9b0c85ea9ba064145958aa5). 

The part of the log file where the crash happened is attached. Not really sure what lead up to it, but I did get an alert from my server monitor telling me my swap space got really low around the time it crashed. 

The OSD reconnected after restarting the service. Currently, I'm waiting patiently as 1 of my 400 pgs gets out of active+clean+scrubbing status. 

Dave Spano 
Optogenics 
Systems Administrator