How to remove a node from a GlusterFS trusted pool

Removing a node from a GlusterFS trusted pool is necessary when decommissioning hardware, retiring a VM, or shrinking a cluster to reduce operational overhead and avoid keeping stale peers in the membership list.

A GlusterFS cluster stores trusted pool membership in its peer metadata, and each peer participates in cluster coordination through the glusterd management layer. Running gluster peer detach removes a peer from that shared membership state so remaining nodes stop treating it as part of the cluster.

A node cannot be detached while it still hosts bricks for any volume, since the cluster would lose the brick definition and risk degraded or unavailable data paths. Ensure all bricks are migrated or removed first, and treat force detach as a last resort for permanently unreachable nodes.

1. List trusted pool peers to confirm the exact Hostname value for the node to detach.

   $ sudo gluster peer status
   Number of Peers: 2
   
   Hostname: node2
   Uuid: 2c1c1b4c-2c9b-4f6c-9c5e-0f0d7b0e6d1a
   State: Peer in Cluster (Connected)
   
   Hostname: node3
   Uuid: 6b7c3b6a-5d7c-4c8a-a8b8-3f4a2e4f5d6a
   State: Peer in Cluster (Connected)

   Use the hostname exactly as shown, including FQDN vs short name.

2. Review volume bricks to confirm the target node is not hosting data.

   $ sudo gluster volume info
   
   Volume Name: volume1
   Type: Replicate
   Volume ID: 1d2c3b4a-5e6f-7a8b-9c0d-1e2f3a4b5c6d
   Status: Started
   Number of Bricks: 1 x 2 = 2
   Bricks:
   Brick1: node1:/srv/gluster/brick1
   Brick2: node2:/srv/gluster/brick1

   Related: How to remove a brick from a GlusterFS volume

3. Detach the node from another server in the trusted pool.

   $ sudo gluster peer detach node3
   Detach successful

   If the node is permanently offline and shows as Disconnected, use sudo gluster peer detach node3 force.

   Detaching a node that still hosts bricks can cause data loss and volume outages.

4. Verify the node no longer appears in peer status.

   $ sudo gluster peer status
   Number of Peers: 1
   
   Hostname: node2
   Uuid: 2c1c1b4c-2c9b-4f6c-9c5e-0f0d7b0e6d1a
   State: Peer in Cluster (Connected)

5. Check volume status to confirm remaining bricks are online after the pool change.

   $ sudo gluster volume status volume1
   
   Status of volume: volume1
   Gluster process                             TCP Port  RDMA Port  Online  Pid
   ------------------------------------------------------------------------------
   Brick node1:/srv/gluster/brick1             49152     0          Y       2143
   Brick node2:/srv/gluster/brick1             49153     0          Y       1987
   Self-heal Daemon on node1                   N/A       N/A        Y       2278
   Self-heal Daemon on node2                   N/A       N/A        Y       2065
   
   Task Status of Volume volume1
   ------------------------------------------------------------------------------
   There are no active volume tasks