PowerScale OneFS Upgrade Planning and Process Guide

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Client connections during rolling upgrades

Rolling upgrades allow users to access data before, during, and after the upgrade. However, as nodes are upgraded and restarted, users may experience brief pauses in the time it takes to complete a read or write operation.

If the cluster is configured for dynamic IP allocation, client connections to restarted nodes are automatically reconnected. If a client is reconnected to a node that has not yet been upgraded and restarted, the client might be required to reestablish a connection to the cluster more than once.

The following table describes the expected client behavior when a node is restarted on a cluster that is configured for dynamic IP allocation:

Table 1. Client BehaviorsThe following table displays the expected behavior for each client.
Client	Expected client behavior
SMB2	Client transitions from the restarting node to a new node, but the client is disrupted. NOTE:In OneFS 9.3.0.0 and later, the client transitions from the restarting node to a new node without disruption.
SMB3	Client transitions from the restarting node to a new node without disruption.
NFSv2 and NFSv3	Client transitions from the restarting node to a new node without disruption.
NFSv4	Client transitions from the restarting node to a new node without disruption. Clients use NFSv4 failover support.

NOTE:If a client is reconnected to a node that has not yet been upgraded, the client might be required to reestablish a connection to the cluster more than once.

NOTE:For more information about NFS settings, see article 457328, Best practices for NFS client settings.