Page of GC20-1821-3 As Updated April 1, 1981 by TNL GN25-0840 The MDISK statements for 330 and 331 define disks for the CP system
residence, paqing, and spooling volumes. This directory entry configuration does not define any other user dIsks, teleprocessing lines, or tape drives. All additionai devices
required for testing VM/370 in a virtual machine can be specified by using the ATTACH, LINK, and DEFINE commands. Virtual Machine Configuration
To run the VM/370 nucleus in a virtual machine, load it onto the
minidisk that represents the virtual system residence volume. Then,
before initializing the system, verify that the virtual machine
configuration has: • The correct console address • sufficient unit record devices available at the correct addresses • Enough disks (either linked or attached) to make a reasonable test When setting up the virtual machine configuration, a user can link to
other user disks so that the VM/370 system can use these disks in its
virtual operation. However, the user must ensure that links to other
disks use the correct addresses and device types.
For example: A real VM/370 system has 2314s defined as 130 to 137
and has 3330s defined as 330 to 337. To avoid operational errors, the
virtual VM/370 system links to user 2314 disks in the range of 130 to
137 and links to user 3330 disks in the range of 330 to 337. If a user
disk is linked to as a 2314 address when it is actually a 3330 or 3340 device, the virtual VM/370 system receives errors when trying to process
that user disk.
DEFINING A CONSOLE FOR VM/370 IN A VIRTUAL MACHINE Since the logon console for a virtual machine operates as a 3215, 3210, or 1052, one of the following two methods can be used to satisfy the
console reqoirements for your VM/370 virtual machine:
1. In the DMKRIO for the second level VM/370 system you are building,
define the console device as DEVTYPE 3215, 3210, or 1052 in the RDEVICE macro (Ex: RDEVICE ADDRESS=01p, DEVTYPE=3215). 2. Another approach is attaching a console-type device to your virtual
machine and using that as your second level VM/370 console. For
example, if your DMKRIO for address 01p defines a DEVTYPE of 3277,
then attach or DIAL a real 3277 to your virtual machine as address 01F to function as your second level VM/370 console. Regardless of which method you choose, you must specify
the CONSOLE directory statement when defining your virtual
operator.
52 IBM VMi370 Operating Systems in a Virtual Mach; 3215 in VM/370

Page of GC20-1821-3 As Updated April 1, 1981 by TNL GN25-0840 CMS SYSTEM For VM/370 in a virtual machine to also run CMS, it must have access to
the eMS system residence volume. The virtual machine can access this
volume either before logon (by using the LINK statement in the directory
entry) or after logon (by using the CP LINK command). If passwords are
provided, the virtual VM/370 system can link to other users' disks so
that they can be used as primary disks by the CMS system. Thus, under
the one userid for the virtual VM/370 system, this system can access all
the disks necessary to do a virtual system VMFLOAD or any other similar
function. 2305 DEVICES It is probably not necessary to have a 2305 paging device in the
configuration unless the test specifically addresses that device. If
this device is required and if the real configuration allows it, the user may define temporary 2305 space for a paging volume. Depending
upon the nature of virtual machine testing, one or more teleprocessing
lines can be defined so that users may use the DIAL command to access
the VM/370 system in a virtual machine. In most cases, simple tests do
not require teleprocessing lines to be defined or enabled at the virtual
machine level. Most testing can be performed by the operator's virtual
machine from the virtual console.
Section 2. VM/370 in a Virtual Machine 52.1