HP 3PAR Online Import for EMC Storage Data Migration Guide

1 Overview of HP 3PAR Online Import for EMC Storage
HP 3PAR Online Import for EMC Storage manages the migration of data from a source EMC
Storage system to a destination HP 3PAR StoreServ Storage system. Using HP 3PAR Online Import
for EMC Storage, you can migrate EMC virtual disks and host configuration information to a
destination HP 3PAR StoreServ Storage system without changing host configurations or interrupting
data access. The term storage system represents array in the screen output examples and may be
used interchangeably as the EMC or HP 3PAR StoreServ Storage systems.
HP 3PAR Online Import for EMC Storage coordinates the movement of data from the source while
servicing I/O requests from the hosts. During the data migration, host I/O is serviced from the
destination HP 3PAR StoreServ Storage system. The host/virtual disk presentation implemented on
the EMC is maintained on the destination HP 3PAR StoreServ Storage system.
Types of Data Migration
The HP 3PAR Online Import Software supports three basic types of data migration procedures.
The appropriate type of data migration is selected automatically based on the objects being
migrated.
• Online—Migration type used when migrating a non-Windows host or a virtual disk presented
to a non-Windows host. During online migration, all presentation relationships between hosts
and virtual disks being migrated are maintained. Host I/O to the data is not disrupted during
an online migration.
• Offline—Migration type used when migrating one or more unpresented virtual disks. During
offline migration, only the selected virtual disks are migrated. No hosts are migrated in this
situation.
• Minimally disruptive—Migration type used when migrating a host or a virtual disk presented
to a host (must be the type used when migrating a Windows host). The host DSM (Device
Specific Module) used to access the storage system must be reconfigured from the EMC DSM
to a DSM that will communicate with the destination HP 3PAR StoreServ Storage system. Host
I/O is interrupted only during the time it takes to reconfigure the host.
NOTE: The HP 3PAR Online Import Utility for EMC Storage (OIU) only supports the Offline
and Minimally Disruptive types of data migration methods.
Understanding What Data is Migrated
Data migration can be done by selecting a host or a virtual disk on the source EMC Storage system.
In addition to the host or virtual disk explicitly selected for migration, other objects may be included
in the migration using implicit selection. A pre-migration process identifies the relationship between
hosts and presented virtual disks and selects all necessary objects to completely migrate the hosts.
Consequently, the explicit selection can lead to many implicit selections and a large amount of
data being migrated. For example, selecting a single host will result in migration of the host, any
virtual disks presented to it, any hosts to which those virtual disks are presented, and any virtual
disks presented to those hosts.
IMPORTANT: The implicit selection of objects for migration is done automatically and cannot be
modified. If the number of objects selected for migration becomes too large, the migration can be
canceled before it is started. Once a migration begins, it cannot be stopped.
The migration process selects objects to migrate using the following rules:
• Host—When selecting a single host or group of hosts with virtual disk presentations, all the
virtual disks presented to the host(s) are migrated. In addition, any presentations the source
6 Overview of HP 3PAR Online Import for EMC Storage