Hello everyone, After upgrading our Ceph cluster from 17.2.7 to 17.2.8 using `cephadm`, all OSDs are reported as unreachable with the following error: ``` HEALTH_ERR 32 osds(s) are not reachable [ERR] OSD_UNREACHABLE: 32 osds(s) are not reachable osd.0's public address is not in '172.20.180.1/32,172.20.180.0/24' subnet osd.1's public address is not in '172.20.180.1/32,172.20.180.0/24' subnet ... osd.31's public address is not in '172.20.180.1/32,172.20.180.0/24' subnet ``` However, all OSDs actually have IP addresses within the `172.20.180.0/24` subnet. The cluster remains functional (CephFS is accessible), and muting the warning with `ceph health mute OSD_UNREACHABLE --sticky` allows normal operation, but the underlying issue persists. ### **Environment Details** - **Ceph Version:** 17.2.8 (f817ceb7f187defb1d021d6328fa833eb8e943b3) Quincy (stable) - **Container Image:** ` quay.io/ceph/ceph@sha256:a0f373aaaf5a5ca5c4379c09da24c771b8266a09dc9e2181f90eacf423d7326f` - **OS:** CentOS Stream 9 - **Deployment Method:** cephadm ### **Network Configuration** The network settings appear correct: ``` ceph config get osd public_network 172.20.180.0/24 ceph config get osd cluster_network 172.20.180.0/24 ceph config get mon public_network 172.20.180.0/24 ceph config get mgr public_network 172.20.180.0/24 ``` OSD metadata confirms that the assigned addresses are in the correct subnet: ``` "front_addr": "[v2: 172.20.180.126:6800/87977614,v1:172.20.180.126:6801/87977614]" ``` ### **Current Cluster Status** - All OSDs are **up** and **in**, and `ceph osd status` reports them as operational. - `ceph orch ps` confirms that OSD services are running. - `ceph mon stat` shows all monitors in quorum. - Cluster services (CephFS, RBD) are working as expected despite the warning. ### **Questions** 1. Has anyone else encountered this issue after upgrading to 17.2.8? 2. Is this a known regression? (This seems similar to issue #67517.) 3. Would upgrading to Ceph 18.x (Reef) resolve the problem? 4. Is there any solution other than muting the health warning? Any insights or recommendations would be greatly appreciated! -- Best regards, Ilya