SnapMirror active sync is supported beginning with ONTAP 9.9.1. Upgrading and reverting your ONTAP cluster has implications on your SnapMirror active sync relationships depending on the ONTAP version to which you are upgrading or reverting.

Upgrade ONTAP with SnapMirror active sync

To use SnapMirror active sync, all nodes on the source and destination clusters must be running ONTAP 9.9.1 or later.

When upgrading ONTAP with active SnapMirror active sync relationships, you should use automated nondisruptive upgrade (ANDU). Using ANDU ensures your SnapMirror active sync relationships are in sync and healthy during the upgrade process.

There are no configuration steps to prepare SnapMirror active sync deployments for ONTAP upgrades. However, it is recommended that before and after the upgrade, you should check that:

SnapMirror active sync relationships are in sync.
There are no errors related to SnapMirror in the event log.
The Mediator is online and healthy from both clusters.
All hosts can see all paths properly to protect LUNs.

When you upgrade clusters from ONTAP 9.9.1 or 9.9.1 to ONTAP 9.10.1 and later, ONTAP creates new consistency groups on both source and destination clusters for SnapMirror active sync relationships that can be configured using ONTAP System Manager.

The snapmirror quiesce and snampirror resume commands are not supported with SnapMirror active sync.

Revert to ONTAP 9.9.1 from ONTAP 9.10.1

To revert relationships from 9.10.1 to 9.9.1, SnapMirror active sync relationships must be deleted, followed by the 9.10.1 consistency group instance. Consistency groups with an active SnapMirror active sync relationship cannot be deleted. Any FlexVol volumes that were upgraded to 9.10.1 previously associated with another Smart Container or Enterprise App in 9.9.1 or earlier will no longer be associated on revert. Deleting consistency groups does not delete the constituent volumes or volume granular snapshots. Refer to Delete a consistency group for more information on this task in ONTAP 9.10.1 and later.

Revert from ONTAP 9.9.1

SnapMirror active sync is not supported with mixed ONTAP clusters than include releases earlier than ONTAP 9.9.1.

When you revert from ONTAP 9.9.1 to an earlier release of ONTAP, you must be aware of the following:

If the cluster hosts an SnapMirror active sync destination, reverting to ONTAP 9.8 or earlier is not allowed until the relationship is broken and deleted.
If the cluster hosts an SnapMirror active sync source, reverting to ONTAP 9.8 or earlier is not allowed until the relationship is released.
All user-created custom SnapMirror active sync policies must be deleted before reverting to ONTAP 9.8 or earlier.

To meet these requirements, see Remove a SnapMirror active sync configuration.

Steps

Confirm your readiness to revert, entering the following command from one of the clusters in the SnapMirror active sync relationship:

cluster::> system node revert-to -version 9.7 -check-only

The following sample output shows a cluster that is not ready to revert with instructions for clean up.

cluster::> system node revert-to -version 9.7 -check-only
Error: command failed: The revert check phase failed. The following issues must be resolved before revert can be completed. Bring the data LIFs down on running vservers. Command to list the running vservers: vserver show -admin-state running Command to list the data LIFs that are up: network interface show -role data -status-admin up Command to bring all data LIFs down: network interface modify {-role data} -status-admin down
Disable snapshot policies.
    Command to list snapshot policies: "snapshot policy show".
    Command to disable snapshot policies: "snapshot policy modify -vserver
   * -enabled false"

   Break off the initialized online data-protection (DP) volumes and delete
   Uninitialized online data-protection (DP) volumes present on the local
   node.
    Command to list all online data-protection volumes on the local node:
   volume show -type DP -state online -node <local-node-name>
    Before breaking off the initialized online data-protection volumes,
   quiesce and abort transfers on associated SnapMirror relationships and
   wait for the Relationship Status to be Quiesced.
    Command to quiesce a SnapMirror relationship: snapmirror quiesce
    Command to abort transfers on a SnapMirror relationship: snapmirror
   abort
    Command to see if the Relationship Status of a SnapMirror relationship
   is Quiesced: snapmirror show
    Command to break off a data-protection volume: snapmirror break
    Command to break off a data-protection volume which is the destination
   of a SnapMirror relationship with a policy of type "vault": snapmirror
   break -delete-snapshots
    Uninitialized data-protection volumes are reported by the "snapmirror
   break" command when applied on a DP volume.
    Command to delete volume: volume delete

   Delete current version snapshots in advanced privilege level.
    Command to list snapshots: "snapshot show -fs-version 9.9.1"
    Command to delete snapshots: "snapshot prepare-for-revert -node
   <nodename>"

   Delete all user-created policies of the type active-strict-sync-mirror
   and active-sync-mirror.
   The command to see all active-strict-sync-mirror and active-sync-mirror
   type policies is:
    snapmirror policy show -type
   active-strict-sync-mirror,active-sync-mirror
   The command to delete a policy is :
    snapmirror policy delete -vserver <SVM-name> -policy <policy-name>

Once you’ve satisfied the requirements of the revert check, see Revert ONTAP.