Selecting your update method for MetroCluster configurations

Based on your requirements, you can update (upgrade or downgrade) a MetroCluster configuration to a different ONTAP release by performing a nondisruptive upgrade or a disruptive upgrade.

Nondisruptive and disruptive updates

Nondisruptive upgrade and downgrade procedures perform the operation while maintaining service to clients.

In a disruptive upgrade or downgrade, storage failover is disabled for each HA pair, and then each node is rebooted one at a time. Disruptive upgrades can be performed more quickly than nondisruptive upgrades, and require fewer steps to complete. However, you should not perform a disruptive upgrade unless you can take the cluster offline for the duration of the upgrade. If you are operating in a SAN environment, you should be prepared to shut down or suspend all SAN clients before performing a disruptive upgrade.

Automated and manual updates

Automated nondisruptive upgrades (NDU) are the preferred method of upgrading a cluster. With NDU, ONTAP automatically installs the target ONTAP image on each node, validates the cluster components to ensure that the cluster can be upgraded nondisruptively, and then executes the upgrade in the background.

Choosing the right procedure

You can use the following table to determine which procedure you should use and whether that procedure is manual or automated, based on the following criteria:

Number of nodes in MetroCluster configuration ONTAP version Nondisruptive? Manual? See...
Two 9.3 and later Yes No Upgrading an ONTAP cluster using the automated method
Two 9.2 and earlier

No for downgrades from ONTAP 9.1; yes for all others

Yes

Updating a two-node MetroCluster configuration in ONTAP 9.2 or earlier

Downgrading a two-node MetroCluster configuration disruptively

Four 9.3 and later Yes No Upgrading an ONTAP cluster using the automated method
Four or eight 9.2 and earlier Yes Yes Updating a four- or eight-node MetroCluster configuration manually
Four or eight, patch upgrades only Any Yes No Software express upgrade
Eight 9.3 and later Yes Yes Updating a four- or eight-node MetroCluster configuration manually
Any Any No Yes Updating an ONTAP cluster disruptively