Ceph

Disclaimer: this might be only present on the current single-paxos branch (maybe due to some mistaken conflict resolution); haven't yet tested this on current master, but am creating the ticket anyway so it doesn't end up forgotten.

ubuntu@plana41:~/ceph.wsp/src$ ./ceph mon remove d
removed mon.d at 127.0.0.1:6792/0, there are now 3 monitors

ubuntu@plana41:~/ceph.wsp/src$ ./ceph mon add d 127.0.0.1:6792
mon d 127.0.0.1:6792/0 already exists

ubuntu@plana41:~/ceph.wsp/src$ ./ceph -s
   health HEALTH_WARN 1 mons down, quorum 0,1,2 a,b,c
   monmap e4: 4 mons at {a=127.0.0.1:6789/0,b=127.0.0.1:6790/0,c=127.0.0.1:6791/0,d=127.0.0.1:6792/0}, election epoch 26, quorum 0,1,2 a,b,c
   osdmap e8: 2 osds: 2 up, 2 in
    pgmap v90: 24 pgs: 24 active+clean; 8730 bytes data, 213 GB used, 642 GB / 901 GB avail
   mdsmap e5: 1/1/1 up {0=a=up:active}

Basically, during 'add', the return message is something on the lines of 'it already exists!' -- which at that point might be true, given we just added it, but if that's the rationale behind said message, it really should be changed for something less prone to misunderstanding.