Hitachi HPAV for z/OS for the XP128/XP1024/XP12000/XP10000 (HITA737-96003, March 2007)

16 HPAV for the XP1024/XP128/XP12000/XP10000
and/or the expected host access rates for the base devices, determine the number of aliases for each
base device to meet your requirements for each base device.
• Up to 255 alias devices can be assigned to one base device. In this case, however, the desired effect
will not be achieved because I/O conflicts can occur with the base device and the alias devices.
Therefore, the devices may be unable to receive the I/Os.
Preparing for HPAV Operations
System Requirements
HPAV operations involve the volumes on the XP1024/XP128/XP12000/XP10000, the licensed Command
View XP or XP Remote Web Console software, and the WLM host software function. The system
requirements for HPAV are:
• Host software:
• For static HPAV: OS/390 V1R3 or later, and DFSMS/MVS® 1.3 or later VM/ESA 2.4.0 or later.
• For dynamic HPAV: OS/390 V2R7 with APAR OW39854, and DFSMS/MVS 1.5 or later.
• APARs and PTFs: The XP1024/XP128/XP12000/XP10000 does not have any specific APAR/PTF
requirements beyond what is required by the z/OS and OS/390 operating system to provide
minimum support for the 2105 or 2107 device type.
• XP1024/XP128/XP12000/XP10000: The emulation type for a CU image that controls HPAV devices
must be 2105 (see ”Changing the Controller Emulation Type” on page 17).
• IOCP definition considerations: If you maintain separate IOCP definitions files and create your SCDS or
IOCDS manually by running the IZP IOCP program, the following definition rules apply:
• Each LCU on an XP1024/XP128/XP12000/XP10000 is defined using one CNTLUNIT statement in
IOCP. The unit type is 2105 or 2107. Up to 16 LCUs can be defined on an
XP1024/XP128/XP12000/XP10000. An LCU is identified by its ‘Control Unit Address’
(‘CUADDR=x’ parameter) and is specified as a hexadecimal number in the range of ‘0’ to ‘F’. An
LCU is the same as an IBM Logical Sub-System or LSS. While it is possible to have an LCU on an
XP1024/XP12000/XP10000 defined using multiple CNTLUNIT statements in IOCP, the resulting
input deck cannot be migrated to HCD due to an IBM restriction to allow only one CNTLUNIT
definition.
• Up to 256 devices may be defined on each LCU. Base device addresses are identified as unit type
3390B. Alias device addresses are identified as 3390A.
• HCD definition considerations: If you use HCD exclusively to define I/O definitions to z/OS and
OS/390 and to automatically run the IOCP program to create SCDS or IOCDS, the following definition
rules apply:
• Each LCU on an XP1024/XP128/XP12000/XP10000 is defined as a 2105 or 2107 control unit.
• Base devices are defined as 3390B device types. HCD will only connect base devices to one
control unit. Base device optional parameter definitions in HCD include the ‘WLMPAV=xxx’
parameter. The default setting is ‘YES’.
• Alias devices are defined as 3390A device types. HCD will only connect alias devices to one
control unit. Alias devices have only one optional parameter definition in HCD. The ‘WLMPAV=xxx’
parameter defaults to ‘YES’.
• Command View XP or XP Remote Web Console: See the HP StorageWorks Command View XP User
Guide for XP Disk Arrays or the HP StorageWorks XP Remote Web Console User Guide for the specific
disk array.
Table 4 Ratio of base devices to alias devices
Ratio
(base devices : alias devices)
Number of Base
Devices
Number of Alias
Devices
Total Devices
1:3 (recommended) 64 192 256 (64+192)
1:2 85 171 (85+86) 256 (85+171)
1:1 128 128 256 (128+128)