Software User Manual

HPAV for z/OS user guide for the XP128/XP1024/XP12000/XP10000 27
4 Performing Compatible PAV Operations
After you have prepared for Compatible PAV operations as described in ”Preparing for Compatible PAV
Operations” on page 23 you are ready to start performing Compatible PAV operations on the
XP1024/XP128/XP12000/XP10000. Compatible PAV operations include:
• Assigning and canceling aliases ( see ”Assigning and Canceling Aliases” on page 27)
• Defining the XP1024/XP128/XP12000/XP10000 devices to the host system (see ”Considerations for
Defining the XP1024/XP128/XP12000/XP10000 Devices to the Host System” on page 30)
Assigning and Canceling Aliases
Assigning Aliases
Before you assign Compatible PAV aliases, you should have determined the required number of aliases for
each base device to meet your operational requirements (see ”Maximizing Your Compatible PAV Results”
on page 20). If you assign additional aliases after starting I/O operations to the
XP1024/XP128/XP12000/XP10000 Compatible PAV devices, you will need to redefine the
XP1024/XP128/XP12000/XP10000 Compatible PAV devices to the host operating system.
You can assign up to 255 (15 for XP1024/128) aliases to one base device. The Compatible PAV assign
alias function pairs each selected base volume with one or more of the selected free volumes. If the number
of selected free volumes is larger than the number of selected base volumes, this function attempts to
allocate the free volumes equally to the base volumes. For example, if six free volumes and two base
volumes are selected, three free volumes (aliases) are allocated to each base volume.
WARNING! When dynamic Compatible PAV is used, you must use a host command to check the number
of aliases assigned to the desired base volume (for details of the host command, refer to section 4.3.2). If
fifteen aliases are already assigned to the base volume, the following procedure will not produce the
desired results because you cannot assign more than fifteen aliases to any base volume.
WARNING! If you use only Compatible Hyper PAV to issue I/O requests to a CU, you can just decide the
number of aliases that are necessary for the CU, and assign the aliases to arbitrary base volumes. The
assigned aliases will work as aliases for all base volumes in the concerned CU. In that case, assign 3 or
less alias devices for one base device.
To assign aliases to volumes in the connected TagmaStore USP subsystem:
1. From the Compatible PAV window, select the CU group which includes the CU number to be set, in the
drop-down list to select CU groups located in the upper right part of the HP XP Remote Web Console
main panel. See the HP StorageWorks XP Remote Web Console User Guide for XP12000/XP10000
for the details.
2. Click the CU image that contains the base volumes. The Free Volume List box displays the total number
of available free volumes.
3. To add the new aliases to the Alias Volume List box, click the base volumes in the Base Volume List box,
click the free volumes in the Free Volume List box, and then click the Å button.
To assign one alias to each base volume, select the same number of free volumes as base volumes.