Hello,

I have an old ceph 0.94.10 cluster that had 10 storage nodes with one extra management node used for running commands on the cluster. Over time we'd had some hardware failures on some of the storage nodes, so we're down to 6, with ceph-mon running on the management server and 4 of the storage nodes. We attempted deploying a ceph.conf change and restarted ceph-mon and ceph-osd services, but the cluster went down on us. We found all the ceph-mons are stuck in the electing state, I can't get any response from any ceph commands but I found I can contact the daemon directly and get this information (hostnames removed for privacy reasons):

root@<mgmt1>:~# ceph daemon mon.<mgmt1> mon_status
{
    "name": "<mgmt1>",
    "rank": 0,
    "state": "electing",
    "election_epoch": 4327,
    "quorum": [],
    "outside_quorum": [],
    "extra_probe_peers": [],
    "sync_provider": [],
    "monmap": {
        "epoch": 10,
        "fsid": "69611c75-200f-4861-8709-8a0adc64a1c9",
        "modified": "2019-08-23 08:20:57.620147",
        "created": "0.000000",
        "mons": [
            {
                "rank": 0,
                "name": "<mgmt1>",
                "addr": "[fdc4:8570:e14c:132d::15]:6789\/0"
            },
            {
                "rank": 1,
                "name": "<mon1>",
                "addr": "[fdc4:8570:e14c:132d::16]:6789\/0"
            },
            {
                "rank": 2,
                "name": "<mon2>",
                "addr": "[fdc4:8570:e14c:132d::28]:6789\/0"
            },
            {
                "rank": 3,
                "name": "<mon3>",
                "addr": "[fdc4:8570:e14c:132d::29]:6789\/0"
            },
            {
                "rank": 4,
                "name": "<mon4>",
                "addr": "[fdc4:8570:e14c:132d::151]:6789\/0"
            }
        ]
    }
}


Is there any way to force the cluster back into a quorum even if it's just one mon running to start it up? I've tried exporting the mgmt's monmap and injecting it into the other nodes, but it didn't make any difference.

Thanks!