Relocating file systems

Replication and Disaster Recovery Administration Guide for Hitachi NAS Platform

Part Number

Storage servers support relocation of file systems, or parts of file systems, including both file system data and file system metadata from one server to another. Metadata refers, for example, to CNS links, SMB shares, NFS mount points, FTP users, Snapshot rules, backup files, and other file system-level settings.

Note: Unlike other file system metadata, iSCSI configuration settings remain with the original EVS, as an iSCSI target may contain Logical Units (LUs) from multiple file systems. In this instance, the Relocation page displays a message, reminding the Administrator to properly configure iSCSI Domains, Targets, iSNS, and Initiator Authentications on the new EVS.

Allowable destinations for a relocation may be:

  • Another EVS on the same cluster node,
  • Another node in the cluster, or
  • An EVS on another server or cluster.

The following list includes some examples of file system relocations:

  • Moving data to a new storage system.
  • Dividing a single large file system into several smaller file systems within a storage pool.
  • Load balancing, by moving data from one file system to another, or by moving a file system from one EVS to another.
  • Moving an EVS (and all its file systems) to another server to gain access to other storage devices or to change the structure of the data.

From a high level, relocating file systems requires two steps:

  1. Replicate online data while the system is live and in normal use. This may require several incremental replications, to synchronize the data on the source and the target as much as possible. Synchronizing the data shortens the amount of time required for the next step.
  2. Perform a final replication with source data (file system) in Syslocked mode. When in Syslocked mode, the data is write-protected, so the data can be accessed and read, but data cannot be changed or added. At the end of this stage, the target is brought online in place of the source. For more information on Syslock mode, refer to the File Services Administration Guide.