Configuring Data Migrator paths

Data Migrator Administration Guide for Hitachi NAS Platform

Part Number

There are different types of paths between primary and secondary storage.

  • Primary storage (typically Fibre Channel disk arrays) is the source for data migrations.
  • Secondary storage (typically SATA disk arrays) is the target for data migrations. Note that there are two types of paths to secondary storage:
    • Local paths - these are paths to secondary storage attached to the same EVS, storage server, or cluster. Local paths can be added using the NAS Manager.
    • External Paths - these are paths to secondary storage that is attached to a remote server (a NAS Platform, or another server using the NFS protocol, or a Hitachi Content Platform using the HTTP protocol). External paths cannot be added using the NAS Manager. Instead, you must use CLI commands.

After Data Migrator has been configured, data is migrated from primary to secondary storage based on the data migration rules and schedules, freeing up space and extending the capacity of the primary storage.

Dysfunctional backups alert! Accessing files directly on secondary storage might alter access and modification times of the files, resulting in unexpected results when performing backups. The organizational structure of migrated data on secondary storage does not mirror that of primary storage.
Lost access to migrated files alert! If only the primary or only the secondary file system is moved to a different EVS, access to migrated files will be lost. If both the primary and the secondary file systems are moved to the same EVS, access to migrated files will be retained. When moving file systems, File System Relocation is the recommended method, because, when using File System Relocation, if the file system being moved is a member of a data migration path, both the data migration source file system and the target file system are relocated. See the File Services Administration Guide for more information.
Exclusive migration pathing! Once a migration path has been assigned to a virtual volume, a subsequent migration path cannot be created to its hosting file system. Also, once a migration path has been assigned to a file system, subsequent migration paths cannot be created from virtual volumes hosted by that file system.
Note: When defining data migration paths, specify a file system or virtual volume as the primary storage. Once a file system is selected as primary storage, that entire file system, including all virtual volumes is included as a part of the data migration policy. Therefore, in order to create individual policies for different parts of a file system, create virtual volumes and assign each virtual volume a unique migration path.