HP MPX200 Multifunction Router - Manual (Page 19)

3 Data migration objects
ThIs chapter covers the objects that the MPX200 DMS uses in data migration.
Arrays
DMS either discovers the FC target ports zoned in with the MPX200 FC ports, or it discovers and
logs into iSCSI qualified name (IQN) targets using iSCSI login. It forms an array when at least one
data LUN is presented to the MPX200 from that array. If no data LUN is presented to the MPX200,
all array ports are shown in the HP mpx Manager GUI and CLI as target ports.
DMS classifies the discovered storage array controllers into two categories: targets and arrays.
All array controller ports are initially identified as targets by the MPX200. After a single data LUN
is detected on the target, DMS forms an entity called an array. A specific LUN seen through multiple
FC target ports or IQN targets are grouped under a single array.
NOTE: The MPX200 may detect a single storage array as two storage arrays if another set of
LUNs are presented to the MPX200 through other target ports of the same array. This scenario
typically occurs when you have large storage arrays such as the EMC-DMX, HP-XP, or IBM DS8000.
Configure the array entity for the DMS using the following attributes:
•
Symbolic name: Upon forming an array, the MPX200 Multifunction Router automatically
assigns it a symbolic name. HP recommends you change the array's symbolic name to a more
meaningful name as the migration log containing source and destination LUNs becomes
associated with that symbolic name.
•
Array type: DMS requires the classification of each array as either Source, Destination,
Source+Destination, or None. The Data Migration wizard, during the creation of migration
jobs, restricts assignment of a source LUN only from arrays that have an attribute Source or
Source+Destination. The wizard restricts assignment of a destination LUN only from arrays
with attribute Destination or Source+Destination. Use the array attribute Source+Destination
only when you need to create copies of a LUN on the same array.
Select the array type attribute None to exclude a storage array from data migration. The
MPX200 simultaneously supports both iSCSI connectivity and data migration service. Typically,
you would use the None attribute when the MPX200 provides only iSCSI connectivity for that
storage array or to define an array only for a data management LUN.
•
Array bandwidth: This feature is applied only to a source array. This value indicates the
maximum bandwidth the MPX200 can use for a data migration task from the source array .
The bandwidth is computed over all paths. The MPX200 is restricted to the user-assigned array
bandwidth to migrate the data. This feature allows other applications and servers using the
same source array to continue to perform at an acceptable performance level. The minimum
bandwidth required for data migration is 50 MBps.
•
Load balancing: The MPX200 detects all available active and passive paths to the LUN. Load
balancing balances the load for migration jobs over multiple active paths, thus improving the
migration rate. Disable load balancing only if there is a problem performing data migration.
NOTE: The MPX200 may detect a single storage array as two storage arrays if another set
of LUNs are presented to the MPX200 through other target ports of the same array. This
scenario typically occurs when you have large storage arrays such as the EMC-DMX, HP-XP,
or IBM DS8000.
•
Maximum Concurrent I/O: Because the source array is in use by hosts that may or may not
be part of the migration process, I/Os to the source array may exceed the maximum concurrent
I/Os supported by the array. Most arrays are equipped to handle this scenario and start
returning the SCSI status as 0x28(TASK SET FULL) or 0x08(BUSY) for the incoming I/Os that
exceed the arrays’ maximum concurrent I/O limit. The TASK SET FULL or BUSY SCSI status
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