Honestly, this sort of thing is what led me a while back to eschew the replication network whenever possible. I have a cluster today from which I'm going to remove it.

On Jun 24, 2026, at 5:50 AM, Eugen Block via ceph-users <ceph-users@ceph.io> wrote:

Hi,

since I just stumbled across 'ceph cephadm config-check', is it enabled in this cluster? Could the MGR have warned you with the health check "CEPHADM_CHECK_NETWORK_MISSING" after adding hosts but before deploying OSDs?

It seems that it's not enabled by default.

And one more question: could 'osd_crush_initial_weight = 0' have prevented this from happening? We have that set in our own cluster to carefully check if all OSDs are deployed correctly before reweighting.

I *suspect* that that wouldn't have prevented this particular situation, but it does inform the idea of incremental deployment of OSDs. Back in the day I tripled the size of a Dumpling cluster. It was not pretty.