Specifications

8 IBM System z Personal Development Tool: Volume 3 Additional Topics
Figure 1-1 CP, processor, and instances
The rules, implied in Figure 1-1, are these:
򐂰 Your 1090 model number (assuming a standard token: L01, L02, or L03) must be greater
than or equal to the number of (CPs + zIIPs +zAAPs + IFLs) in your total configuration.
򐂰 You must have fewer (CPs + zIIPs + zAAPs + IFLs) in a single instance than there are
processors in your underlying PC hardware.
1.7 CKD versioning
A function is available to allow an emulated 3390 (or 3380) volume to be “reset” to a selected
point in time. This function is known as CKD versioning. The usage is as follows:
򐂰 A command is issued for selected emulated volumes (which might be all the emulated
volumes in your configuration) to enable versioning. This must be done when zPDT is not
active.
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򐂰 zPDT is started, an operating system is IPLed, and the volumes are used in the normal
way.
򐂰 At a later time (when zPDT is not running), commands are issued to either commit
whatever changes were made to the volumes, or restore the volumes to the exact content
it had when CKD versioning was enabled for it.
A typical use might be for a demonstration or benchmark run. After the demonstration or
benchmark run is completed, the volumes can be restored to their original state.
A CKD-emulated volume can be considered to have two versions. Version zero is the original
state of the volume and version one is a volume that has been changed after versioning was
1090: CP
PC
core
1090: CP CP
PC
core
1090: CP
PC
core
1090: CP 1090: CP
PC
core
1090: CP 1090: CP
1090: CP CP
PC
core
PC
core
1090: CP zIIP
PC
core
1090: CP
PC
core
1090: CP CP zAAP
PC
core
PC
core
PC
core
PC
core
1090: CP CP
PC
core
1090: CP
PC
core
PC
core
PC
core
One 1090 instance.
One CP defined.
Invalid. More CPs in one
instance than cores.
Two instances. Valid
but underpowered.
Three instances. Valid but
severely underpowered.
Not supported in Version 1
Release 3 or later. You must
have at least one more core than
the number of CPs in the largest
instance, except in the one
CP/one core case.
One instance. SMP. Two instances, including one SMP
(A zIIP counts as a CP).
One instance. SMP. Good power. Two instances. SMP. Good power.
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zPDT can be active if the selected volumes are not in the active devmap.