Upgrade requirements for SnapMirror

You must perform certain tasks to successfully upgrade a cluster that is running SnapMirror.

• If you are upgrading clusters with an inter-cluster DP SnapMirror relationship, you must upgrade the destination cluster before you upgrade the source cluster.

• Before upgrading a cluster that is running SnapMirror, SnapMirror operations must be suspended for each node that contains destination volumes, and each peered SVM must have a unique name across the clusters.

  For SnapMirror volume replication, the destination node must use an ONTAP version that is equal to or later than that of the SnapMirror source node. To prevent SnapMirror transfers from failing, you must suspend SnapMirror operations and, in some cases, upgrade destination nodes before upgrading source nodes. The following table describes the two options for suspending SnapMirror operations.

  Option	Description	Upgrade destination nodes before source nodes?
  Suspend SnapMirror operations for the duration of the NDU (nondisruptive upgrade).	The simplest method for upgrading in a SnapMirror environment is to suspend all SnapMirror operations, perform the upgrade, and then resume the SnapMirror operations. However, no SnapMirror transfers will occur during the entire NDU. You must use this method if your cluster contains nodes that are mirroring volumes to each other.	No, the nodes can be upgraded in any order.
  Suspend SnapMirror operations one destination volume at a time.	You can suspend SnapMirror transfers for a particular destination volume, upgrade the node (or HA pair) that contains the destination volume, upgrade the node (or HA pair) that contains the source volume, and then resume the SnapMirror transfers for the destination volume. By using this method, SnapMirror transfers for all other destination volumes can continue while the nodes that contain the original destination and source volumes are upgraded.	Yes.

SVM peering requires SVM names to be unique across clusters. You should name SVMs with a unique fully qualified domain name (FQDN), for example, dataVerser.HQ or mirrorVserver.Offsite. Using the FQDN naming style makes it much easier to make sure of uniqueness.