Loading and Saving Discontiguous Saved Segments
Loading and Saving the CMSVSAM and CMSAMS Segments When a VSAM routine is invoked, CMS attaches the discontiguous segments
that contain the VSAM simulation routines. When an access method
services routine is invoked, CMS attaches the discontiguous segments
that contain the access method services routines.
The VSAMGEN installation EXEC procedure helps you load VSAM and access method services segments. The VSAMGEN procedure can be used to: • Install VSAM and access method services for DOS users • Install VSAM amd access method services for as users • Update VSAM amd access method services for DOS users • Update VSAM and access method services for as users
Before you invoke VSAMGEN, you must:
and save the
installation • Restore a Release 31 (or later) DOS/VS starter tape to disk. The
disks supported by DOS/VS Release 31, 32, and 33 are: 2314/2319, 3330 Modell and 11, 3340, 3344, and 3350. In DOS/VS Release 34 the 3330
Model 11 and the 3350 (native mode) are also supported. For a
description of the procedure for restoring a starter tape, see the
publication System • Generate VM/370 and apply the latest level of PLC updates. • Install the CMS/DOS saved segment called INSTVSAM. • Define the size of your virtual machine so that it is large enough to
contain the six VSAM segments and the eight access method services
segments, plus at least two additional segments: one for the CMS control blocks and free storage used during the generation process,
and one for the CMS/DOS segment called CMSDOS. However, your machine
must not be so large that it overlays the CMS/DOS segment called INSTVSAM. The CMSVSAM and CMSAMS segments must be loaded so that they do not
overlay each other, the virtual machine that is loading them, or ani
other discontiguous segment that will be loaded at the same time. CMSVSAM and CMSAMS also must be loaded at addresses lower than the CMS/DOS segment called INSTVSAM and beyond the area where you loaded
the CMSSEG segment. CMSSEG contains the CMS Editor, EXEC processor,
and as simulation routines.
If you follow the example shown in Figure 31, define your virtual
machine storage size as 2112K. • Access your A-disk in read/write mode. The VSAMGEN EXEC procedure
writes DOSLIB files, updated object modules, and (for the as user) CMS text files created from VSAM and access method services object
modules to the A-disk. Before the VSAMGEN EXEC procedure completes,
it prompts you to specify whether you want to save the DOSLlBs created; if not, it erases them. If you are following the example shown, answer "yes" to this prompting message. The amount of space
you need on your A-disk depends on (1) the device type of your A-disk
and (2) whether you are an OS or DOS user. The amount of A-disk
space required is:
Part 3. Generating VM/370 (CP, CMS, RSCS, and IPCS) 271

Loading and Saving Discontiguous Saved Segments Device
Type
2314
2319 3330 1
33 30 11 3340 3344 3350 Number of DOS User 10 10 6
6
15
15
3
Cylinders Required:
as User 20 20 12
12 30 30 6 DOS users can use the MlINT 191 supplied with the starter
system to generate VSAM and access method services without obtaining
additional minidisk space, but they must erase the DOSLIBs when
asked. as users should define sufficient A-disk space as indicated
in the table. • IPL a CMS system with sufficient virtual storage (in the example
shown in Figure 31, 2 112K) :
define storage 2112K
ipl 190 parm seg=null • Since the CMS/DOS segment called INSTVSAM is used to install the CMSVSAM and CMSAMS segments, you must define the system name of the CMS/DOS segment. To do this, issue the command:
set sysname cmsdos instvsam
Then link to and access the restored DOS/VS starter system.
cp link dos 342 342 rr read
access 342 d
set dos on d
The S-disk must be accessed as a read-only extension of the A-disk.
access 190 b/a
Invoke the VSAMGEN EXEC procedure by entering:
vsamgen VSAMGEN prompts you to enter INSTALL if you are installing VSAM and
access method services or UPDATE if you are updating the already
installed VSAM and access method services routines.
requires that you indicate whether you are an as
prompting messages are: DMSVGN360R ENTER 'INSTALL' 'UPDATE' OR 'RESTART' DMSVGN361R ENTER EITHER 'DOS' OR 'OS' or VSAMGEN also DOS user. The
Respond INSTALL and DOS or as. If
all system modules are transferred
the CMS disk in TEXT file format.
dispose of the DOS starter system.
user, reply as a DOS user. INSTALL is specified for an as user,
from the DOS relocatable library to
This allows the as installation to
If you are both an OS and a DOS VSAMGEN requires a read/write A-disk
available. If an A-disk is not available,
following error messages and terminates: DMSVGN069E DISK 'A' NOT ACCESSED. DMSVGN361E DISK 'A' IS NOT A CMS DISK. and checks that one is VSAMGEN issues one of the
272 IBM VM/370 Planning and System Generation Guide