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Remove nodes from the cluster

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You can remove unwanted nodes from a cluster, one node at a time. After you remove a node, you must also remove its failover partner. If you are removing a node, then its data becomes inaccessible or erased.

Before you begin

The following conditions must be satisfied before removing nodes from the cluster:

  • More than half of the nodes in the cluster must be healthy.

  • All of the data on the node that you want to remove must have been evacuated.

  • All non-root volumes have been moved from aggregates owned by the node.

  • All non-root aggregates have been deleted from the node.

  • If the node owns Federal Information Processing Standards (FIPS) disks or self-encrypting disks (SEDs), disk encryption has been removed by returning the disks to unprotected mode.

  • Data LIFs have been deleted or relocated from the node.

  • Cluster management LIFs have been relocated from the node and the home ports changed.

  • All intercluster LIFs have been removed.

    • When you remove intercluster LIFs a warning is displayed that can be ignored.

  • Storage failover has been disabled for the node.

  • All LIF failover rules have been modified to remove ports on the node.

  • All VLANs on the node have been deleted.

  • If you have LUNs on the node to be removed, you should modify the Selective LUN Map (SLM) reporting-nodes list before you remove the node.

    If you do not remove the node and its HA partner from the SLM reporting-nodes list, access to the LUNs previously on the node can be lost even though the volumes containing the LUNs were moved to another node.

It is recommended that you issue an AutoSupport message to notify NetApp technical support that node removal is underway.

Note: You must not perform operations such as cluster remove-node, cluster unjoin, and node rename when an automated ONTAP upgrade is in progress.

About this task

  • If you are running a mixed-version cluster, you can remove the last low-version node by using one of the advanced privilege commands beginning with ONTAP 9.3:

    • ONTAP 9.3: cluster unjoin -skip-last-low-version-node-check

    • ONTAP 9.4 and later: cluster remove-node -skip-last-low-version-node-check

  • If you unjoin 2 nodes from a 4-node cluster, cluster HA is automatically enabled on the two remaining nodes.

Note All system and user data, from all disks that are connected to the node, must be made inaccessible to users before removing a node from the cluster. If a node was incorrectly unjoined from a cluster, contact NetApp Support for assistance with options for recovery.
Steps

  1. Change the privilege level to advanced:

    set -privilege advanced

  2. Verify if a node on the cluster holds epsilon:

    cluster show -epsilon true

  3. If a node on the cluster holds epsilon and that node is going to be unjoined, move epsilon to a node that is not going to be unjoined:

    1. Move epsilon from the node that is going to be unjoined

      cluster modify -node <name_of_node_to_be_unjoined> -epsilon false

    2. Move epsilon to a node that is not going to be unjoined:

      cluster modify -node <node_name> -epsilon true

  4. Identify the current master node:

    cluster ring show

    The master node is the node that holds processes such as “mgmt”, “vldb”, “vifmgr”, “bcomd”, and “crs”.

  5. If the node you want to remove is the current master node, then enable another node in the cluster to be elected as the master node:

    1. Make the current master node ineligibly to participate in the cluster:

      cluster modify – node <node_name> -eligibility false

      When the master node become ineligible, one of the remaining nodes is elected by the cluster quorum as the new master.

    2. Make the previous master node eligible to participate in the cluster again:

      cluster modify – node <node_name> -eligibility true

  6. Log into the remote node management LIF or the cluster-management LIF on a node other than the one that is being removed.

  7. Remove the node from the cluster:

    For this ONTAP version…​ Use this command…​

    ONTAP 9.3

    		 
    cluster unjoin

    ONTAP 9.4 and later

    		 
    cluster remove-node*

    If you have a mixed version cluster and you are removing the last lower version node, use the -skip-last-low-version-node-check parameter with these commands.

    The system informs you of the following:

    • You must also remove the node's failover partner from the cluster.

    • After the node is removed and before it can rejoin a cluster, you must use boot menu option (4) Clean configuration and initialize all disks or option (9) Configure Advanced Drive Partitioning to erase the node's configuration and initialize all disks.

      A failure message is generated if you have conditions that you must address before removing the node. For example, the message might indicate that the node has shared resources that you must remove or that the node is in a cluster HA configuration or storage failover configuration that you must disable.

      If the node is the quorum master, the cluster will briefly lose and then return to quorum. This quorum loss is temporary and does not affect any data operations.

  8. If a failure message indicates error conditions, address those conditions and rerun the cluster remove-node or cluster unjoin command.

    The node is automatically rebooted after it is successfully removed from the cluster.

  9. If you are repurposing the node, erase the node configuration and initialize all disks:

    1. During the boot process, press Ctrl-C to display the boot menu when prompted to do so.

    2. Select the boot menu option (4) Clean configuration and initialize all disks.

  10. Return to admin privilege level:

    set -privilege admin

  11. Repeat the preceding steps to remove the failover partner from the cluster.