Hi,

This is issue with CephFS snapshot mirroring setup between two clusters and would appreciate your assistance.

Environment:

• Primary Cluster: Ceph 15.2.13/16.2.5 (mixed versions)
  
• Backup Cluster: Ceph 17.2.7/18.2.7 (mixed versions)
  
• Filesystem: cephfs
• Issue: Unable to import peer bootstrap token

Problem Description:

When attempting to import a peer bootstrap token using:

ceph fs snapshot mirror peer_bootstrap import cephfs <token>

I receive the error:

Error EEXIST: already an active peer mgr.server reply reply (17) File exists already an active peer

However, ceph fs snapshot mirror peer_list cephfs returns an empty list [], indicating no peers are configured.

Steps Performed:

Initial Setup:

1. Enabled mirroring module: ceph mgr module enable mirroring

2. Deployed cephfs-mirror service: ceph orch apply cephfs-mirror

3. Enabled mirroring on filesystem: ceph fs snapshot mirror enable cephfs

4. Created remote user and bootstrap token on backup cluster

5. Verified mirroring daemons are running: ceph fs snapshot mirror daemon status

Troubleshooting Attempts:

1. Reset filesystem mirroring:

ceph fs snapshot mirror disable cephfs
ceph fs snapshot mirror enable cephfs

2. Module reset:

ceph mgr module disable mirroring
ceph mgr module enable mirroring

3. Service recreation:

ceph orch rm cephfs-mirror
ceph orch apply cephfs-mirror

4. Checked for stale configuration:

o ceph config-key ls | grep mirror shows: mgr/cephadm/spec.cephfs-mirror

o ceph fs snapshot mirror dirmap cephfs returns empty

o ceph fs snapshot mirror status cephfs shows no active mirroring

Current Status:

• Mirroring daemons: Running and visible in daemon status
• Peer list: Empty []
• Filesystem mirroring: Enabled
• Error persists: EEXIST despite no visible peers

Diagnostic Information:

• MGR logs show: mgr.server reply reply (17) File exists already an active peer
• No connectivity issues between clusters (ports 6789, 3300, 6800+ tested)
• Both clusters are healthy with no other issues

Regards,

Anantha