SYSLOCS P!acro SYSLOCS Macro
The SYSLOCS macro instruction is a required macro used to generate
internal pointer variables. This must be the last macro in the DMKSYS deck.
This macro is required and must be the last macro in the DMKSYS file.
The name field must not be specified for the SYSLOCS macro
instruction. No operands are required for the SYSLOCS macro; if one is
specified, it is ignored.
The format of the SYSLOCS macro is:
r , Name , Operation
i SYSLOCS L- Operands
An example of the SYSLOCS macro is: SYSLOCS IBP! VM/370 Planning and System Generation Guide

Page of GC20-1801-10 As Updated April 1, 1981 by TNL GN25-0837
Directory
Creating Your VM/370 Directory
The VM/370 directory contains the entries of all potential virtual
machines that are permitted to logon the VM/370 system. Without the
proper directory entry, a user cannot log on to VM/370. The entries in
the directory contain the user identification and password, the virtual
machine I/O configuration, associated virtual and real addresses, disk
usage values, virtual processor storage size, and other options. These
options are discussed in the directory program control statement
descr ipt ions.
Each user in the directory, except those whose password is NOLOG, must have at least one device. Any of the various devices described meet
this requirement; for example, the device may be a console or a spool
device. The number of virtual devices for a virtual machine cannot
exceed the value determined by (7FFF/VDEVSIZE), where VDEVSIZE is the
size of the VDEVBLOK. If a greater number of virtual devices is
specified, results may be undesirable.
The VM/370 directory usually resides on the VM/370 system residence
disk, and is pointed to by the VOL1 label (cylinder 0, track 0, record
3). The VM/370 Directory program (module DMKDIR, invoked by the DIRECT
command, or run standalone) processes the control statements you prepare
and writes the VM/370 directory on disk. You already described your
installation's real configuration when you created the real I/O configuration file. NOw, you describe the many virtual configurations
for your installation with the Directory program control statements.
To create a VM/370 directory, you must: • Prepare the Directory program control statements • Format and allocate the DASD space to contain the VM/370 directory • Execute the Directory program At this time, you should prepare the Directory program control
statements. Later, during the system generation procedure, you must (1)
format and allocate DASD space for the VM/370 directory and (2) generate
it. The step-by-step description of the system generation procedure that
is in Part 3 of this manual reminds you to create your VM/370 directory.
Considerations for Preparing the Directory Control
Statements
First, prepare a directory control statement that defines the device on
which the VM/370 directory is to be written. This statement (DIRECTORY) must be the first control statement in the input to the Directory
program, and is followed by the sets of statements describing your
installation's virtual machines.
Next, prepare Directory proqram control statements describing each
virtual machine in your installation. The descriptions contain
accountinq data, options, and virtual machine configurations for each
virtual machine that appears in the VM/370 directory. Information about
coding these control statements is found in the section, "The Directory
Proqram. " VM/370 does not check for overlapping extents; therefore, you must
ensure that minidisk extents defined in the VM/370 directory do not
overlap each other and (in the case of 3330, 3340, and 3350 disks) do
not overlap the "alternate track" cylinders. If overlap conditions
exist, file data damage is inevitable. Part 2. Defining Your VM/370 System 183