Main And Remote Control Units (Mcus And Rcus); Raid-Level Configurations For Continuous Access Xp - HP xp12000 User Manual

copies of the P-VOLs. Continuous Access XP supports all CU images and logical volumes of the disk array
and all physical hard drive options. Continuous Access XP supports RAID1, RAID5, and RAID6
configurations for the XP12000/XP10000.
Table 3 shows RAID-level configurations for Continuous Access XP.
Table 3

RAID-level configurations for Continuous Access XP

RAID level of P-VOL
RAID1
RAID5
RAID6
To provide greater flexibility and enable the disk array to be tailored to unique customer operating
requirements, additional operational parameters, or optional modes, are available for the disk array. At
installation, modes are set to their default values, so discuss these settings with your HP support team.
Modes can only be changed by your HP support team representative.
Contact your HP account support representative for the latest mode information.

Main and remote control units (MCUs and RCUs)

The main control unit (MCU) and remote control unit (RCU) control Continuous Access XP operations:
• The MCU is the control unit in the primary disk array that controls the P-VOLs of the Continuous Access
XP volume pairs. For Command View XP, the management station must be LAN-attached to the MCU of
each Continuous Access XP pair. For XP Remote Web Console and Command View XP, you need
connectivity between the array managed in the environment and the Web clients used to manage
them. The MCU communicates with the RCU via dedicated Fibre Channel remote copy connections.
The MCU controls host I/O operations to the Continuous Access XP P-VOLs and Continuous Access XP
initial copy and remote copy operations between the P-VOLs and S-VOLs. The MCU also manages
Continuous Access XP pair status and configuration information.
• The RCU is the CU in the remote disk array that controls the S-VOLs of the Continuous Access XP
volume pairs. The RCU assists in managing Continuous Access XP pair status and configuration (for
example, rejects write I/Os to Continuous Access XP S-VOLs). The RCU executes remote copy
operations issued by the MCU. For Command View XP, the management station must be LAN-attached
to the RCU of each Continuous Access XP pair. For XP Remote Web Console and Command View XP,
you need connectivity between the array managed in the environment and the Web clients used to
manage them. The RCUs should also be attached to a host system to allow sense information to be
reported if a problem with a secondary volume or remote disk array occurs and provide disaster
recovery capabilities.
You can define the MCU and RCU whether or not you specify the CU image. To define the MCU and RCU
and specify the CU image, specify the desired CU image. To define the MCU and RCU without specifying
the CU image, specify CU Free. For more information, see
The MCU and RCU can be defined separately for each Continuous Access XP volume pair. The
XP12000/XP10000 CU can function simultaneously as an MCU for one or more P-VOLs and as an RCU
for one or more S-VOLs, provided the remote copy connections and Fibre Channel or serial interface ports
are properly configured. The XP12000/XP10000 provides up to 32 logical CU images (0-1F), with each
CU image controlling up to 256 logical devices (LDEVs). To define the MCU and RCU and specify the CU
image, use Continuous Access XP to select the desired CU image in the connected MCU and specify the
desired CU image in the RCU. Continuous Access XP operations can be performed on all LDEVs except the
XP12000/XP10000 command device.
RAID level of S-VOL
RAID1
Supported
Supported
Supported
Continuous Access XP user guide for the XP12000/XP10000
RAID5
Supported
Supported
Supported
"Registering RCUs (Add
RAID6
Supported
Supported
Supported
RCU)" on page 66.
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