Ceph

Lack of logging doesn't help that much in assessing what may be going on, but the stack trace might prove itself useful.

    -3> 2013-06-06 10:01:12.445236 7face4a63700  1 -- 192.168.168.200:6789/0 --> osd.15 192.168.168.201:6816/2819 -- mon_subscribe_ack(300s) v1 -- ?+0 0x6700540
    -2> 2013-06-06 10:01:12.662171 7face4a63700  1 -- 192.168.168.200:6789/0 <== mds.? 192.168.168.201:6800/1853 731 ==== mdsbeacon(1572925/b up:standby seq 10995 v609) v2 ==== 279+0+0 (1046463253 0 0) 0x8feb2c0 con 0x454fc60
    -1> 2013-06-06 10:01:12.662463 7face4a63700  1 -- 192.168.168.200:6789/0 --> 192.168.168.201:6800/1853 -- mdsbeacon(1572925/b up:standby seq 10995 v609) v2 -- ?+0 0x2ba5000 con 0x454fc60
     0> 2013-06-06 10:01:14.191192 7face5264700 -1 mon/PaxosService.h: In function 'void PaxosService::request_proposal(PaxosService*)' thread 7face5264700 time 2013-06-06 10:01:14.170594
mon/PaxosService.h: 301: FAILED assert(other->is_writeable())

 ceph version 0.61.2 (fea782543a844bb277ae94d3391788b76c5bee60)
 1: /usr/bin/ceph-mon() [0x51ea69]
 2: (MDSMonitor::tick()+0x1b82) [0x528f02]
 3: (Monitor::tick()+0x5d) [0x4abffd]
 4: (Context::complete(int)+0xa) [0x4bf38a]
 5: (SafeTimer::timer_thread()+0x425) [0x63fa75]
 6: (SafeTimerThread::entry()+0xd) [0x6406ad]
 7: (()+0x7e9a) [0x7facea058e9a]
 8: (clone()+0x6d) [0x7face8cf3ccd]
 NOTE: a copy of the executable, or `objdump -rdS <executable>` is needed to interpret this.