Administrator Guide

Table 3. Types of data mobility operations (continued)
Batch Moves data using a migration plan file. Create batch
migrations to automate routine tasks.
● Use batched device migrations to migrate to dissimilar
arrays and to migrate devices within a cluster and between
the clusters in a metro node Metro configuration.
Technology refresh
In typical IT environments, migrations to new storage arrays (technology refreshes) require that the data that is being used
by hosts be copied to a new volume on the new array. The host must then be reconfigured to access the new storage. This
process requires downtime for the host.
Metro node makes it easier to replace heterogeneous storage arrays on the back-end. Migrations between heterogeneous
arrays can be complicated and may require additional software or functionality. Integrating heterogeneous arrays in a single
environment is difficult and requires a staff with a diverse skill set.
When metro node is inserted between the front-end and back-end redundant fabrics, metro node appears as the target to hosts
and as the initiator to storage.
The data resides on virtual volumes in metro node and it can be copied nondisruptively from one array to another without any
downtime. There is no need to reconfigure the host; the physical data relocation is performed by metro node transparently and
the virtual volumes retain the same identities and the same access points to the host.
In the following figure, the virtual disk is made up of the disks of Array A and Array B. The site administrator has determined that
Array A has become obsolete and should be replaced with a new array. Array C is the new storage array. Using Mobility Central,
the administrator:
● Adds Array C into the metro node cluster.
● Assigns a target extent from the new array to each extent from the old array.
● Instructs metro node to perform the migration.
Metro node copies data from Array A to Array C while the host continues its access to the virtual volume without disruption.
After the copy of Array A to Array C is complete, Array A can be decommissioned:
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Metro node use cases