File system relocation

File Service Administration Guide for Hitachi NAS Platform

Version
14.9.x
Audience
anonymous
Part Number
MK-92HNAS006-31

Before it can be shared or exported, a file system must be associated with a Virtual Server (EVS), thereby making it available to network clients. The association between a file system and an EVS is established when the file system is created. Over time, evolving patterns of use and/or requirements for storage resources may make it desirable to relocate a file system to a different EVS.

Note: Read caches cannot be relocated.

A file system hosted by an EVS on a cluster node may be relocated to:

  • An EVS on the same cluster node, or
  • An EVS on a different node in the same cluster.

    but may not be relocated to:

  • An EVS on a stand-alone server, or
  • An EVS on a node of a different cluster.
A file system hosted by an EVS on a stand-alone server may be relocated to
  • An EVS on the same server

    but may not be relocated to:

  • An EVS on a different server, or
  • An EVS on a node in a cluster.

Typically, File System Relocation is used to move a file system from an EVS on a cluster node to an EVS on a different cluster node in order to improve throughput by balancing the load between cluster nodes.

File system relocation performs the following operations:
  • Re-associates the file system with the selected EVS.
  • Transfers explicit CIFS shares of the file system to the new EVS.
  • Transfers explicit NFS exports of the file system to the new EVS.
  • Migrates FTP users to the new EVS.
  • Migrates snapshot rules associated with the file system to the new EVS.
  • Migrates the iSCSI LUs and targets.

File system relocation may require relocating more than just the specified file system. If the file system is a member of a data migration path, both the data migration source file system and the target file system will be relocated. It is possible for the target of a data migration path to be the target for more than one source file system. If a data migration target is relocated, all associated source file systems will be relocated as well.

If more than one file system must be relocated, a confirmation dialog will appear indicating the additional file systems that must be moved. Explicit confirmation must be acknowledged before the relocation will be performed.

File System Relocation will affect the way in which network clients access the file system in any of the following situations:
  • The file system is linked to from the CNS tree, but is shared or exported outside of the context of the CNS.
  • The cluster does not use a CNS.

In each of the above cases, access to the shares and exports will be changed. In order to access the shares and exports after the relocation, use an IP address of the new EVS to access the file service.

Relocating file systems that contain iSCSI Logical Units (LUs) will interrupt service to attached initiators, and manual reconfiguration of the IP addresses through which targets are accessed will be required once the relocation is complete. If relocating a file system with LUs is required, the following steps must be performed:
  • Disconnect any iSCSI Initiators with connections to LUs on the file system to be relocated.
  • Unmount the iSCSI LU.
  • Relocate the file system as normal. This procedure is described in detail in the Replication and Disaster Recovery Administration Guide.
  • Reconnect the new Targets with the iSCSI Initiators. Be aware that the Targets will be referenced by a new name corresponding to the new EVSs.
Note: All iSCSI LUs on a target must be associated with file systems hosted by the same EVS.