VM/370 storage Requirements
The primary system operator is warned when the paging/spooling space
becomes 901 full. The !!/37Q manual tells the operator
what he should do if this warning occurs. VSAM AND ACCESS METHOD SERVICES REQUIREMENTS The VSAM and access method services support in CMS requires both DASD space and virtual storage.
The amount of DASD space needed is listed in Part 3, in the section,
"Loading and Saving the CMSVSAM and CMSAMS Segments." The VSAM and access method services support adds approximately 2K to
the size of the CftS nucleus. In addition, this support uses free
storage to execute the DOS/VS logical transients and for buffers and
work areas. VSAM issues a GETVIS macro to request free storage.
If the CMS/DOS environment is invoked with the VSAM option
set dos on {vsam
part of the CMS/DOS virtual storage is set aside for VSAM use. IPCS Requirements IPCS supports the same basic Vft/370 processor configurations that are
supported by other components of VM/370 with a minimum of 3S4K of real
storage. This is the basic VM/370 requirement.
EXTERNAL STORAGE The disk storage needed by IPCS is divided into two parts. The first
part does not vary greatly (only problem reports and symptom summary are
affected). It contains the IPCS command modules, the current NUC MAP, problem reports, and the symptom summary. These files occupy less than
5 cylinders on a 3330, allocated as shown: • 100 problem reports plus symptom summary 201 • NUC MAP 451 • IPCS modules 35" The second part contains the dumps. The size of a dump depends mainly
on the size of the system being dumped, and the operand of the CP SET DUMP command, either ALL or CP. The table below shows typical space
usage by device type for the fixed area and for one dump.
92 IBM VM/370 Planning and System Generation Guide

VM/370 Storage Requirements
r , I Cylinders , I I I Files 3330 2319 3340 3350 , I I I I PCS modules I , NUC MAP I I problem reports 5 9 14 3 I I symptom summary I I I I 51-2K CP 1.5 3 4 1 , I 512K ALL 2.5 5 7 1.5 I I 1024K CP 3 6 a 1.5 I I 1024K ALL 6 11 16 3 I L
REAL STORAGE The real storage requirement is the normal CP requirement of
approximately 2K for control blocks while the IPCS virtual machine is
logged on. Other real storage usage is controlled by the VM/370 demand
paging implementation.
Estimating DASD Storage Requirements for eMS The following information is intended to help you allocate sufficient
direct access storage space for CMS minidisks. A 2314 cylinder formatted by the CMS FORMAT command contains 150 aOO-byte blocks, which can contain approximately 1300 aO-byte lines of
source programs and data. A 3330 cylinder formatted by the CMS FORMAT command contains 266
BOO-byte blocks, which can contain approximately 2300 aO-byte lines of
source programs and data. A 3340 cylinder formatted by the CMS FORMAT command contains 96 SOO-byte blocks, which can contain approximately 960 80-byte lines of
source programs and data.
A 3350 cylind'er formatted by the CMS FORMAT command contains 570 aOO-byte blocks, which can contain approximately 5000 aO-byte lines of
source programs and data.
Each BOO-byte block contains file control information as well as your
data. A given amount of data requires more file information if put into
many small files instead of a few large files.
For an average CMS user, the following minidisk space should be
sufficient: • 7 cylinders of 2314 space (for approxilla tely 9100 aO-byte lines of
source programs and data) • 4 cylinders of 3330 space (for approximately 9600 . aO-byte lines of
source programs and data) • 11 cylinders of 3340 space (for approximately 10560 aD-byte lines of
source programs and data) • 2 cylinders of 3350 space (for approximately 9120 aO-byte lines of
source programs and data. Part 1. Planning for System Generation 93