Performance Guidelines
The number of cylinders you calculate here is the number you reserve
on your system residence device using theFORMAT program DMKFMT. You need this information to code the SYSRES macro of your CP system control (DMKSYS) file correctly.
If you do not reserve enoughDASD space for your CP nucleus, the
nucleus overlays other cylinders when it is written on the system
residence volume and may itself be overlaidby other disk writes. VIRTUAL STORAGE REQUIREMENTS When you are generating VM/370 you have three constraints on the maximum
virtual=real size you can specify: real storage, virtual storage, and
the size of your nucleus.
Before you load theCP nucleus, be sure the virtual machine you are
using has enough virtual storage to contain:• CMS (320K) • CP nucleus size (including the virtual=real area)
If your virtual machine does not have enough virtual storage, redefine
storage and1PL again before continuing. SPECIFYING THE AMOUNT OF VIRTUAL=REAL SPACE If you are generating your VK/370 system to include a virtual=real
machine, in step 16 of the system generation procedure you respond"yes" to the system message: VIRTUAL=REAL OPTION REQUIRED (YES, NO) : You are then prompted to enter the size of the virtual=real machine
size:STORAGE SIZE OF VIRT=REAL (MINIMUM IS 32K): you would not want to specify the largest virtual=real machine
possible, since that wouldleave few-page frames available for other
virtual machines.
AtIPL time, the virtual=real area is locked in storage immediately
followingCP page O. The system operator can issue the UNLOCK command
with theVIRT=REAL option to free the virtual=real area for additional
dynamic paging space for other virtual machines. The area cannot be
relocked; it remains unlocked until another systemIPL. Calculate the maximum amount of virtual=real storage available on
your realCPU as follows: • Use Formula 1 to calculate the amount of real storage above the
minimum requiredby CP at IPL time. If available real storage (ARS) is negative or zero, CP will not IPL. • Use Formula 2 to calculate the
any real machine size. IfVRS area is not supported.
maximum virtual=real size(VRS) for
is negative or zero, a virtual=realPart 1. Planning for System Generation 11
The number of cylinders you calculate here is the number you reserve
on your system residence device using the
If you do not reserve enough
nucleus overlays other cylinders when it is written on the system
residence volume and may itself be overlaid
virtual=real size you can specify: real storage, virtual storage, and
the size of your nucleus.
Before you load the
using has enough virtual storage to contain:
If your virtual machine does not have enough virtual storage, redefine
storage and
machine, in step 16 of the system generation procedure you respond
size:
possible, since that would
virtual machines.
At
following
with the
dynamic paging space for other virtual machines. The area cannot be
relocked; it remains unlocked until another system
your real
minimum required
any real machine size. If
maximum virtual=real size
is negative or zero, a virtual=real