NFS export on the LNAS used by HNAS

Data Migrator Administration Guide for Hitachi NAS Platform

Part Number

The export from the LNAS should have the following options set: rw, sync, no_subtree_check, no_root_squash. These options allow the HNAS to fully control the data and metadata of the files and directories. The export must also be configured to only allow access to the HNAS, as if other clients are able to access the data with rw and no_root_squash, then the HNAS's view of the data will not be consistent, and it will lose track of what has been virtualized or migrated. This could result in data loss.

Note: If you are restricting the LNAS access on a per-IP basis on the export, include all IP addresses that an EVS can utilize.

The export should only contain real (not virtual) file systems. Examples of virtual file systems are directories such as /dev or /proc on a Linux server, or /.snapshot on a NAS device. It may be difficult or impossible to exclude /.snapshot, or similar, via the LNAS configuration. In this case the directory should be excluded at the HNAS using the virtualization-path-excluded-directory-* commands. The HNAS file system uses its storage resources in different ways to the LNAS; therefore, you cannot depend on the space being used being identical on each. Furthermore, during the process of virtualization and migration, the HNAS file system needs to use extra storage space to track the state of the processing.

The following arrangements on the LNAS should be avoided, as they will lead to unpredictable behavior.
  1. Nesting or overlapping exports on the LNAS used for associations.
  2. Hard links across multiple LNAS exports.