Cluster type	Supported models	Supported features	Maximum supported cluster nodes
AFF	ETERNUS AX/AC series	Automated Failover Duplex (Symmetric Active/Active), Automated Failover (Asymmetric Active/Active)	2 (ONTAP 9.9.1 or later) 4 (ONTAP 9.16.1 with Symmetric Active/Active configurations)
ASA	ETERNUS AX/AC series ASA	Automated Failover Duplex (Symmetric Active/Active), Automated Failover (Asymmetric Active/Active)	2 (ONTAP 9.9.1 or later 4 (ONTAP 9.16.1 with Symmetric Active/Active configurations)
ASA r2	ETERNUS AX1300 ASA ETERNUS AX2300 ASA ETERNUS AX4200 ASA ETERNUS AC2200 ASA	Automated Failover Duplex (Symmetric Active/Active)	2

Cluster type

Supported models

Supported features

Maximum supported cluster nodes

AFF

ETERNUS AX/AC series

Automated Failover Duplex (Symmetric Active/Active), Automated Failover (Asymmetric Active/Active)

2 (ONTAP 9.9.1 or later)
4 (ONTAP 9.16.1 with Symmetric Active/Active configurations)

ASA

ETERNUS AX/AC series ASA

Automated Failover Duplex (Symmetric Active/Active), Automated Failover (Asymmetric Active/Active)

2 (ONTAP 9.9.1 or later
4 (ONTAP 9.16.1 with Symmetric Active/Active configurations)

ASA r2

ETERNUS AX1300 ASA
ETERNUS AX2300 ASA
ETERNUS AX4200 ASA
ETERNUS AC2200 ASA

Automated Failover Duplex (Symmetric Active/Active)

The table below outlines the capability for replication between cluster types.

Cluster type 1	Cluster type 2	Replication supported?
ETERNUS AX series	ETERNUS AC series	Yes
ETERNUS AX1300 ASA ETERNUS AX2300 ASA ETERNUS AX4200 ASA	ETERNUS AC2200 ASA	Yes
ETERNUS AX/AC series	ETERNUS AX/AC series ASA	No
ETERNUS AX/AC series ASA	ETERNUS AX1300 ASA ETERNUS AX2300 ASA ETERNUS AX4200 ASA ETERNUS AC2200 ASA	No
ETERNUS AX1300 ASA ETERNUS AX2300 ASA ETERNUS AX4200 ASA ETERNUS AC2200 ASA	ETERNUS AX1300 ASA ETERNUS AX2300 ASA ETERNUS AX4200 ASA ETERNUS AC2200 ASA	Yes

Cluster type 1

Cluster type 2

Replication supported?

ETERNUS AX series

ETERNUS AC series

Yes

ETERNUS AX1300 ASA
ETERNUS AX2300 ASA
ETERNUS AX4200 ASA

ETERNUS AC2200 ASA

Yes

ETERNUS AX/AC series

ETERNUS AX/AC series ASA

ETERNUS AX1300 ASA
ETERNUS AX2300 ASA
ETERNUS AX4200 ASA
ETERNUS AC2200 ASA

Yes

Software

ONTAP 9.9.1 or later
ONTAP Mediator 1.2 or later
A Linux server or virtual machine for ONTAP Mediator running one of the following:

ONTAP Mediator version	Supported Linux versions
1.10	Red Hat Enterprise Linux Compatible: 9.5 ¹ Recommended: 10, 9.6, 9.4, and 8.10 Rocky Linux 10, 9.6, and 8.10
1.9.1	Red Hat Enterprise Linux Compatible: 9.3, 9.1, 8.9, 8.7, 8.6, 8.5, and 8.4 ¹ Recommended: 9.5, 9.4, 9.2, 9.0, 8.10, and 8.8 Rocky Linux 9.5 and 8.10
1.9	Red Hat Enterprise Linux Compatible: 9.3, 9.1, 8.9, 8.7, 8.6, 8.5, and 8.4 ¹ Recommended: 9.5, 9.4, 9.2, 9.0, 8.10, and 8.8 Rocky Linux 9.5 and 8.10
1.8	Red Hat Enterprise Linux: Compatible: 8.7, 8.6, 8.5, and 8.4 ¹ Recommended: 9.4, 9.3, 9.2, 9.1, 9.0, 8.10, 8.9, and 8.8 Rocky Linux 9.4 and 8.10
1.7	Red Hat Enterprise Linux: Compatible: 8.7, 8.6, 8.5, and 8.4 ¹ Recommended: 9.3, 9.2, 9.1, 9.0, 8.9, and 8.8 Rocky Linux 9.3 and 8.9
1.6	Red Hat Enterprise Linux: Compatible: 8.7, 8.6, 8.5, and 8.4 ¹ Recommended: 9.2, 9.1, 9.0, and 8.8 Rocky Linux 9.2 and 8.8
1.5	Red Hat Enterprise Linux: 8.5, 8.4, 8.3, 8.2, 8.1, 8.0, 7.9, 7.8, 7.7, and 7.6 CentOS: 7.9, 7.8, 7.7, and 7.6
1.4	Red Hat Enterprise Linux: 8.5, 8.4, 8.3, 8.2, 8.1, 8.0, 7.9, 7.8, 7.7, and 7.6 CentOS: 7.9, 7.8, 7.7, and 7.6
1.3	Red Hat Enterprise Linux: 8.3, 8.2, 8.1, 8.0, 7.9, 7.8, 7.7, and 7.6 CentOS: 7.9, 7.8, 7.7, and 7.6
1.2	Red Hat Enterprise Linux: 8.1, 8.0, 7.9, 7.8, 7.7, and 7.6 CentOS: 7.9, 7.8, 7.7, and 7.6

Compatible means that Red Hat no longer supports these RHEL versions, but ONTAP Mediator can still be installed on them.

Licensing

SnapMirror synchronous license must be applied on both clusters.
SnapMirror license must be applied on both clusters.

If your ONTAP storage systems were purchased before June 2019, contact our support to get the required SnapMirror synchronous license.

Networking environment

Inter-cluster latency round trip time (RTT) must be less than 10 milliseconds.

Supported protocols

SnapMirror active sync supports SAN protocols.

The FC and iSCSI protocols are supported beginning with ONTAP 9.9.1.
The NVMe protocol is supported with VMware workloads beginning with ONTAP 9.17.1.

SnapMirror active sync does not support the following with the NVMe protocol:
- 4-node symmetric active/active configurations
- Changes in consistency group size
  
  You cannot expand or shrink a consistency group when using the NVMe protocol with SnapMirror active sync.
- Coexistence of LUNs and namespaces in the same consistency group is not supported.

IPspace

The default IPspace is required by SnapMirror active sync for cluster peer relationships. Custom IPspace is not supported.

NTFS Security Style

NTFS security style is not supported on SnapMirror active sync volumes.

ONTAP Mediator

ONTAP Mediator must be provisioned externally and attached to ONTAP for transparent application failover.
To be fully functional and to enable automatic unplanned failover, the external ONTAP Mediator should be provisioned and configured with ONTAP clusters.
ONTAP Mediator must be installed in a third failure domain, separate from the two ONTAP clusters.
When installing ONTAP Mediator, you should replace the self-signed certificate with a valid certificate signed by a mainstream reliable CA.
For more information about ONTAP Mediator, see Prepare to install ONTAP Mediator.

Other prerequisites

SnapMirror active sync relationships are not supported on read-write destination volumes. Before you can use a read-write volume, you must convert it to a DP volume by creating a volume-level SnapMirror relationship and then deleting the relationship. For details, see Convert an existing SnapMirror relationships to SnapMirror active sync.
Storage VMs using SnapMirror active sync cannot be joined to Active Directory as a client computed.

Further information

ONTAP Mediator overview

ONTAP 9 Manuals ( CA08871-402 )

Prerequisites for ONTAP SnapMirror active sync

Hardware