You must understand how your StorageGRID system will be affected during the upgrade.
The StorageGRID system can ingest and retrieve data from client applications throughout the upgrade process. Grid nodes are brought down one at a time during the upgrade, so there is not a time when all grid nodes are unavailable.
When you upgrade to StorageGRID 11.4, the history for most legacy attributes is trimmed to 30 days. After you upgrade, StorageGRID will allow the attribute history to grow for up to three years. The exception to this is the history for node capacity attributes, S3 rate attributes, and ILM summary attributes, which is trimmed to three years when you upgrade, instead of 30 days.
If you need to retain a longer history for legacy attributes, you must perform either of the following tasks before you upgrade to StorageGRID 11.4:
Exporting text reportsin the instructions for monitoring and troubleshooting StorageGRID).
Alerts and alarms might be triggered when services start and stop and when the StorageGRID system is operating as a mixed-version environment (some grid nodes running an earlier version, while others have been upgraded to a later version). For example, you might see the Unable to communicate with node alert when services are stopped, or you might see the Cassandra communication error alert when some nodes have been upgraded to StorageGRID 11.4 but other nodes are still running StorageGRID 11.3.
In general, these alerts and alarms will clear when the upgrade completes.
When you upgrade grid nodes, a large number of alarm email notifications are generated when the node is stopped and restarted. To avoid excessive emails, you can use the Notification Suppress All check box ( ) to disable alarm notifications before you starting the upgrade. You can re-enable alarm email notifications after the upgrade is completed.