Recovering from primary Admin Node failures

You must complete a specific set of tasks to recover from a primary Admin Node failure. The primary Admin Node hosts the Configuration Management Node (CMN) service for the grid.

About this task

A failed primary Admin Node should be replaced promptly. The Configuration Management Node (CMN) service on the primary Admin Node is responsible for issuing blocks of object identifiers for the grid. These identifiers are assigned to objects as they are ingested. New objects cannot be ingested unless there are identifiers available. Object ingest can continue while the CMN is unavailable because approximately one month's supply of identifiers is cached in the grid. However, after cached identifiers are exhausted, no new objects can be added.

Attention: You must repair or replace a failed primary Admin Node within approximately a month or the grid might lose its ability to ingest new objects. The exact time period depends on your rate of object ingest: if you need a more accurate assessment of the time frame for your grid, contact technical support.

Steps

  1. Copying audit logs from the failed primary Admin Node
    If you are able to copy audit logs from the failed primary Admin Node, you should preserve them to maintain the grid's record of system activity and usage. You can restore the preserved audit logs to the recovered primary Admin Node after it is up and running.
  2. Replacing the primary Admin Node
    To recover a primary Admin Node, you must first replace the node.
  3. Configuring the replacement primary Admin Node
    The replacement node must be configured as the primary Admin Node for your StorageGRID system.
  4. Restoring the audit log on the recovered primary Admin Node
    If you were able to preserve the audit log from the failed primary Admin Node, you can copy it to the primary Admin Node you are recovering.
  5. Resetting the preferred sender on the recovered primary Admin Node
    If the primary Admin Node you are recovering is currently set as the preferred sender of notifications and AutoSupport messages, you must reconfigure this setting in the StorageGRID system.
  6. Restoring the Admin Node database when recovering a primary Admin Node
    If you want to retain the historical information about attribute values and alarms on a primary Admin Node that has failed, you can restore the Admin Node database. This database can only be restored if your StorageGRID system includes another Admin Node.
  7. Restoring Prometheus metrics when recovering a primary Admin Node
    Optionally, you can retain the historical metrics maintained by Prometheus on a primary Admin Node that has failed. The Prometheus metrics can only be restored if your StorageGRID system includes another Admin Node.
Parent topic: Recovering from Admin Node failures
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Part number: 215-13582_2019-08_en-us
August 2019