Requirements for using asynchronous mirroring

If you plan to use asynchronous mirroring, keep the following requirements in mind.

SANtricity Unified Manager

To enable and configure mirroring between two arrays, you must use the Unified Manager interface. Unified Manager is installed on a host system along with the Web Services Proxy.

Storage arrays

Note: Mirroring is not available on the EF600 or EF300 storage array.
  • You must have two storage arrays.
  • Each storage array must have two controllers.
  • The two storage arrays must be discovered in Unified Manager.
  • Each controller in both the primary array and secondary array must have an Ethernet management port configured and must be connected to your network.
  • The storage arrays have a minimum firmware version of 7.84. (They can each run different OS versions.)
  • You must know the password for the local and remote storage arrays.
  • You must have enough free capacity on the remote storage array to create a secondary volume equal to or greater than the primary volume that you want to mirror.
  • Your local and remote storage arrays are connected through a Fibre Channel fabric or iSCSI interface.

Supported connections

Asynchronous mirroring can use either FC or iSCSI connections, or both for communication between local and remote storage systems. At the time of creating a mirror consistency group, the administrator can select either FC or iSCSI for that group if both are connected to the remote storage array. There is no failover from one channel type to the other.

Asynchronous mirroring uses the storage array’s host-side I/O ports to convey mirrored data from the primary side to the secondary side.

Mirrored volume candidates

  • RAID level, caching parameters, and segment size can be different on the primary and secondary volumes of an asynchronous mirrored pair.
  • The secondary volume must be at least as large as the primary volume.
  • A volume can participate in only one mirror relationship.

Reserved capacity

  • A reserved capacity volume is required for a primary volume and for a secondary volume in a mirrored pair for logging write information to recover from controller resets and other temporary interruptions.
  • Because both the primary volume and the secondary volume in a mirrored pair require additional reserved capacity, you must ensure that you have free capacity available on both storage arrays in the mirror relationship.

Drive Security feature

  • If you are using secure-capable drives, the primary volume and the secondary volume must have compatible security settings. This restriction is not enforced; therefore, you must verify it yourself.
  • If you are using secure-capable drives, the primary volume and the secondary volume should use the same drive type. This restriction is not enforced; therefore, you must verify it yourself.
  • If you are using Data Assurance (DA), the primary volume and the secondary volume must have the same DA settings.