System Control File
separate volumes from users' read/write minidisks. If possible, also
keep them on separate channels. If your installation is likely to have a large number of C!S users
active at one time, you should distribute the CMS activity over two
volumes by (1) setting up a second CMS system residence volume and
dividing the users between the two C!S system residence volumes or
(2) putting your program products on one spindle and the CMS non-resident commands on another spindle. If your entire paging area can be contained in the fixed head area of
a 3340 or 3350, you should place it there. To do this, use the
Format/Allocate program to allocate the fixed head area as temporary
space; this should be the only temporary space allocated on that
volume. Then specify PAGE for that volume when you code the SYSOWN macro during system generation. The relative amounts of free storage used for dynamic paging and free
storage can be by using the FREE operand of the SYSCOR macro statement. You should allocate one page of fixed free storage
for each virtual machine that is logged on, based on the average
number of users that you expect to have logged on at anyone time. Using the automatic monitoring facilities, study the load environment
and performance profile for your system as soon as possible. These
facilities, used with programs similar to the IBM PDP (Field
Developed program) Virtual Machine Facility/370: Performance/Monitor
Analysis Program are designed to make data collection and reduction
easy, thereby allowing the analyst to concentrate on analysis. Data
collection can be performed on a regular basis by specifying AUTO=YES on the SYSMON macro instruction. The system will assume the default
values for the other operands if none are specified. Part 2. Defining YOUr VM/370 System 165
SYS OWN Macro SYSOWN Macro Use the SYSOWN macro to generate the list of up to 255 CP-owned DASD volumes. A CP-owned volume is either the CP system residence volume, or
a volume that contains VM/370 paging, spooling, or temporary disk space.
It must contain a CP allocation table at cylinder 0, record 4 allocating
these areas. Even if a volume has a VM/370 allocation table at cylinder 0, record 4, allocation data is ignored unless the volume appears as an
operand in the SYSOWN macro instruction. The SYSOWN macro must appear before the SYSRES macro in the
assembly listing. !;;2nside!:at,i.2!!§ !or !lIQ£ating on CP-Qwned Vol,gj!es: The
following considerations should help you to allocate space efficiently
on CP-owned volumes: If a volume is specified in a SYSOWN statement but is not mounted when the system is Inad@d (via the IPL c0mmand). that volume is considered unavailable to VM/370. Processing continues, if
possible. The operator can mount and attach the volume later, if it
is needed. Only those volumes that contain paging and spooling space or TDSK space need be identified as CP-owned volumes. All other volumes are
described either by directory entries or by logically attaching the
entire device. If you add another volume to the SYSOWN list, you must add it at the
end of the list. (Otherwise, if you attempt a warm start after
regenerating and loading CP, the relative entry number used to locate
system spool buffers is incorrect.) Then reassemble DMKSYS, rebuild
the CP nucleus, and reload it on the system residence volume. Use the GENERATE EXEC procedure to reassemble D8KSYS and reload the CP nucleus. If your installation has saved systems (systems that can be loaded by
name, thus bypassing the initial program load procedure), you must
reserve space on a CP-owned volume to hold the named systems you want
saved. The DASD space you reserve, for each named system you wish to
save, should be enough to contain the number of pages specified in
the SYSPGCT operand of the NA8ESYS macro, plus one page for system
use. If your V8/370 system has a 3704 or 3705, you must reserve space on a CP-owned volume to contain the 3704/3705 control program image. See the "Generating a V8/370 System that Supports the 3704/3705" section
of Part 1 for information about how much DASD space you should
reserve.
The name field must not be specified for the SYSOWN macro. The
format of the SYSOWN macro is:
r I Name , Operation I Operands 1---1-------1 I I , r, r, I I SYSOWN I (volid I ,TEMP I) [, (volid I I) ] I I I I,PAGEI I,PAGEI I I I L J L J L
166 IBM V8/370 Planning and System Generation Guide
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