EVS migration within a server farm (HNAS server only)

Server and Cluster Administration Guide for Hitachi NAS Platform

Version
15.1.x
Audience
anonymous
Part Number
MK-92HNAS010-35

Server Farm Migration is designed to move EVSs between live HNAS systems in order to allow for growth and to move server load between systems at the EVS level. Both systems must be online and functional. Server Farm Migration not only moves the storage but also the EVS settings from the system registry.

Note: This feature is not intended for disaster recovery. To move an EVS from a system that is offline, perform a partial registry restore by EVS. This requires you to have a registry backup of the source system.

Migration within a server farm is supported under the following conditions:

  • When the source EVS is online.
  • When both the source and destination servers are online.
  • If the EVS does not contain any file systems that are linked into a CNS tree.
  • When both the source and destination server have the same major firmware revision.
  • There is no more than one EVS in a storage pool. EVS sharing is not supported with Server Farm Migration.

After migrating EVS between servers in a server farm, the assignment of tape drives and tape autochanger devices to EVS must be manually adjusted:

  • Tape devices specifically assigned to a migrated EVS will have become unassigned.
  • Tape devices assigned to “any EVS” on the source server will remain assigned to “any EVS” on the source server.

Tape devices must not be assigned to EVSs on more than one server.

While EVSs contain most of the settings required to support client storage access, some settings (for example, DNS, which is typically a cluster-wide setting) are functions of the server or cluster, not of the EVS itself. Therefore, when preparing to migrate an EVS from one server or cluster to another, verify in advance that the target server’s settings can properly support the EVS. To prepare a server or cluster to receive a new EVS, source server settings can be cloned.