Specifications

Chapter 4. z/VM notes 65
򐂰 The first real user definition is for MAINT. The first line of this section begins with the
keyword IDENTITY. This is a new keyword that is significant for multiple linked z/VM
systems (new with release 6.2). In a simple environment, the IDENTITY statement is
equivalent to a USER statement.
򐂰 Ignore the SUBCONFIG statements, but observe that many statements are “commented
out” by an asterisk in the first column.
򐂰 LINK statements refer to a minidisk owned by another user. For example, in MAINT’s
directory definitions:
LINK PMAINT 2CC 2CC MR
means that the minidisk at address 2CC in user PMAINT’s definitions is used at address
2CC in this user’s virtual machine.
A simple user definition might be added as shown in Figure 4-8 (these lines would be added
to the directory between two existing user entries, or at the end).
Figure 4-8 Simple user definition
In this example, the userid is BILL and the password is W2WO. The virtual machine is
128 MB, which is more than ample for CMS. The IPL statement causes an automatic IPL of
CMS when user BILL logs onto z/VM. The SPOOL statements are probably not used for
simple situations but are traditional. A console is needed and 009 is a traditional address. The
LINK statements point to other users’ minidisks (all in read-only mode).
The MDISK statement defines a new minidisk at BILL’s address 191. (This is the traditional
address for the “A” disk.) This statement notes that the device is a 3390 with volser VMCOM2,
with the minidisk starting on cylinder 1667 and it is 10 cylinders long. The MR operand
specifies basic read/write access.
How was the cylinder number (1667) obtained? A command is used to map all the minidisks
defined in the directory; new minidisks then can be defined on free cylinders. (On a larger,
production z/VM system all this is usually done by the DIRMAINT program.) The following
command (run by MAINT) runs the diskmap program against the file user direct c, which is
the directory source file:
diskmap user direct c
*
***************************************************
*
* USER BILL IS TO DEMONSTRATE A SIMPLE VM USERID
*
USER BILL W2WO 128M 128M G
MACH ESA
CPU 0
IPL 190
SPOOL 00C 2540 READER *
SPOOL 00D 1403 A
CONSOLE 009 3215 T
LINK MAINT 0190 0190 RR
LINK MAINT 019D 019D RR
LINK MAINT 019E 019E RR
LINK TCPMAINT 592 592 RR
MDISK 191 3390 1667 10 VMCOM2 MR
*
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