Considerations when using ONTAP in a MetroCluster configuration

When using ONTAP in a MetroCluster configuration, you should be aware of certain considerations for licensing, peering to clusters outside the MetroCluster configuration, performing volume operations, NVFAIL operations, and other ONTAP operations.

Licensing considerations

Both sites should be licensed for the same site-licensed features.
All nodes should be licensed for the same node-locked features.

SnapMirror consideration

SnapMirror SVM disaster recovery is only supported on MetroCluster configurations running versions of ONTAP 9.5 or later.

MetroCluster operations in ONTAP System Manager
Depending on your ONTAP version, some MetroCluster-specific operations can be performed using ONTAP System Manager.
FlexCache support in a MetroCluster configuration
Starting with ONTAP 9.7, FlexCache volumes are supported on MetroCluster configurations. You should be aware of requirements for manual repeering after switchover or switchback operations.
FabricPool support in MetroCluster configurations
Starting with ONTAP 9.7, MetroCluster configurations support FabricPool storage tiers.
FlexGroup support in MetroCluster configurations
Job schedules in a MetroCluster configuration
In ONTAP 9.3 and later, user-created job schedules are automatically replicated between clusters in a MetroCluster configuration. If you create, modify, or delete a job schedule on a cluster, the same schedule is automatically created on the partner cluster, using Configuration Replication Service (CRS).
Cluster peering from the MetroCluster site to a third cluster
Because the peering configuration is not replicated, if you peer one of the clusters in the MetroCluster configuration to a third cluster outside of that configuration, you must also configure the peering on the partner MetroCluster cluster. This is so that peering can be maintained if a switchover occurs.
LDAP client configuration replication in a MetroCluster configuration
Networking and LIF creation guidelines for MetroCluster configurations
You should be aware of how LIFs are created and replicated in a MetroCluster configuration. You must also know about the requirement for consistency so that you can make proper decisions when configuring your network.
SVM disaster recovery in a MetroCluster configuration
Starting with ONTAP 9.5, active storage virtual machines (SVMs) in a MetroCluster configuration can be used as sources with the SnapMirror SVM disaster recovery feature. The destination SVM must be on the third cluster outside of the MetroCluster configuration.
Output of the storage disk show and storage shelf show commands in a two-node stretch MetroCluster configuration
In a two-node stretch MetroCluster configuration, the is-local-attach field of the storage disk show and storage shelf show commands shows all of the disks and storage shelves as local, regardless of the node to which they are attached.
Output for the storage aggregate plex show command is indeterminate after a MetroCluster switchover
When you run the storage aggregate plex show command after a MetroCluster switchover, the status of plex0 of the switched over root aggregate is indeterminate and is displayed as failed. During this time, the switched over root is not updated. The actual status of this plex can only be determined after the MetroCluster healing phase.
Modifying volumes to set the NVFAIL flag in case of switchover
You can modify a volume so that the NVFAIL flag is set on the volume in the event of a MetroCluster switchover. The NVFAIL flag causes the volume to be fenced off from any modification. This is required for volumes that need to be handled as if committed writes to the volume were lost after the switchover.
Monitoring and protecting the file system consistency using NVFAIL
The -nvfail parameter of the volume modify command enables ONTAP to detect nonvolatile RAM (NVRAM) inconsistencies when the system is booting or after a switchover operation. It also warns you and protects the system against data access and modification until the volume can be manually recovered.