Deleting a node from a clustered system by using the management GUI

Remove a node from a system if the node failed and is being replaced with a new node, or if a repair causes that node to be unrecognizable by the system.

Before you begin

The cache on the selected node is flushed before the node is taken offline. In some circumstances, such as when the system is already degraded (for example, when both nodes in the I/O group are online and the volumes within the I/O group are degraded), the system ensures that data loss does not occur as a result of deleting the only node with the cache data. If a failure occurs on the other node in the I/O group, the cache is flushed before the node is removed to prevent data loss.

Before you delete a node from the system, record the node serial number, worldwide node name (WWNN), all worldwide port names (WWPNs), and the I/O group that the node is currently part of. If the node is re-added to the system later, recording this node information now can avoid data corruption.

Attention:
  • If you are removing a single node and the remaining node in the I/O group is online, the data on the remaining node goes into write-through mode. This data can be exposed to a single point of failure if the remaining node fails.
  • If the volumes are already degraded before you remove a node, redundancy to the volumes is degraded. Removing a node might result in a loss of access to data and data loss.
  • Removing the last node in the system destroys the system. Before you remove the last node in the system, ensure that you want to destroy the system.
  • When you remove a node, you remove all redundancy from the I/O group. As a result, new or existing failures can cause I/O errors on the hosts. The following failures can occur:
    • Host configuration errors
    • Zoning errors
    • Multipathing-software configuration errors
  • If you are deleting the last node in an I/O group and there are volumes that are assigned to the I/O group, you cannot remove the node from the system if the node is online. You must back up or migrate all data that you want to save before you remove the node. If the node is offline, you can remove the node.
  • When you remove the configuration node, the configuration function moves to a different node within the system. This process can take a short time, typically less than a minute. The management GUI reattaches to the new configuration node transparently.
  • If you turn the power on to the node that has been removed and it is still connected to the same fabric or zone, it attempts to rejoin the system. The system tells the node to remove itself from the system and the node becomes a candidate for addition to this system or another system.
  • If you are adding this node into the system, ensure that you add it to the same I/O group that it was previously a member of. Failure to do so can result in data corruption.

This task assumes that you have already accessed the management GUI.

About this task

Complete the following steps to remove a node from a system:

Procedure

  1. Select Monitoring > System.
  2. Right-click the node that you want to remove and select Remove.

    If the node that you want to remove is shown as Offline, then the node is not participating in the system.

    If the node that you want to remove is shown as Online, deleting the node can result in the dependent volumes to also go offline. Verify whether the node has any dependent volumes.

  3. To check for dependent volumes before you attempt to remove the node, right-click the node and select Show Dependent Volumes.

    If any volumes are listed, determine why and if access to the volumes is required while the node is removed from the system. If the volumes are assigned from storage pools that contain flash drives that are located in the node, check why the volume mirror, if it is configured, is not synchronized. There can also be dependent volumes because the partner node in the I/O group is offline. Fabric issues can also prevent the volume from communicating with the storage systems. Resolve these problems before you continue with the node removal.

  4. Click Remove.
  5. Click Yes to remove the node. Before a node is removed, the system checks to determine if there are any volumes that depend on that node. If the node that you selected contains volumes within the following situations, the volumes go offline and become unavailable if the node is removed:
    • The node contains flash drives and also contains the only synchronized copy of a mirrored volume
    • The other node in the I/O group is offline
    If you select a node to remove that has these dependencies, another panel displays confirming the removal.
Parent topic: Management GUI interface