G Data Migration Best Practices; Overview; Terminology; Relationship Between Application Data And Physical Storage - HP StorageWorks 6400/8400 - Enterprise Virtual Array User Manual

G Data migration best practices

This appendix provides end-to-end "best practices" for using the HP StorageWorks MPX200 data
migration service. The MPX200 data migration service migrates the data at block level. When data
migration is successful, the application is able to access the same data after the data is migrated to
a new logical unit number (LUN). Proper planning for data migration reduces downtime and creates
first-pass success.

Overview

In a typical storage area network (SAN), the storage array serves one or more servers. When data
is migrated from a source LUN to a destination LUN on a different storage array or the same storage
array, it is important to understand the following:
• Which applications and servers (or cluster) are affected?
• How is application data related to physical storage?
• How does the server access old and new physical storage?
A single blade of the MPX200 can deliver a migration rate of up to 4TB/hr. Following the suggestions
outlined in this guide may allow you to perform most migration jobs using simple offline migration
while meeting application downtime requirements, thus removing the complexity of performing online
data migration using other data migration tools.

Terminology

This appendix uses the following terms:
• Mount point—A node or a directory where application data is stored.
• Volume—A single, logical presentation of one or more physical disks.
• Physical disk—The raw disk device discovered and configured in the operating system. The object
represented in the operating system is usually associated to a LUN on a storage array.
• Multi-pathing software—The LUN may be accessed through multiple ports on a storage array.
Each port of a storage array may be accessed through multiple ports (adapters) in the server.
Multi-pathing software in the host manages the multiple paths to a LUN.

Relationship between application data and physical storage

Successful data migration requires that you understand the relationship between the application data
and the physical device (LUN).
NOTE:
The UNIX operating system in this discussion refers to HP-UX, Linux, Solaris, and AIX.
Typically, the application accesses the data using a mount point. For example:
MPX200 Multifunction Router 369