system Control File
The DMKSYS module supplied with the 3330 starter system is: DMKSYS CSECT SYSOWN (VMRELn
1 ,TEMP) SYSRES SYSVOL=VMRELn,SYSRES=131,SYSTYPE=3330,SYSNUC=7, SYSWRM=10,SYSERR=1',SYSCKP=202 SYSOPR SYSOPER=OPERATOR,SYSDUMP=OPERATNS SYSCOR RMSIZE=512K SYSTIME ZONE=4,LOC=WEST,ID=EDT SYSMON AUTO=NO SYSJRL SYSLOCS END
The DMKSYS module supplied with the 3340 starter system is: DMKSYS CSECT SYSOWN (VMRELn
1 ,TEMP) x SYSRIS SYSVOL=VMRELn,SYSRES=131,SYSTYPE=3340,SYSNUC=15, X (17U.3) SYSOPR SYSOPER=OPERATOR,SYSDUMP=OPERATNS SYSCOR RMSIZE=512K SYSTIME ZONE=4,LOC=WEST,ID=EDT SYSMON AUTO=NO SYSJRL SYSLOCS END
The DMKSYS module that is used with the 3350 starter system is: DMKSYS CSECT SYSOWN (VMRELn
1
,TEMP) SYSRES SYSVOL=VMRELn,SYSRES=131,SYSTYPE=3350,SYSNUC=4, SYSWRM=6, SYSERR=7.,SYSCKP=,277 SYSOPR SYSOPER=OPERATOR,SYSDUMP=OPERATNS SYSCOR RMSIZE=512K SYSTIME ZONE=4,LOC=WEST,ID=EDT SYSMON AUTO=NO SYSJRL SYSLOCS END
Performance Considerations for Coding the DMKSYS File Macros X The following recommendations may help reduce arm and channel contention
and may improve the performance of a VM/370 system. • Provide separate CP volumes for paging and spooling and have the
volumes mounted on separate channels. • If you have a heavy I/O production virtual machine (for example, one
that is executing OS/VS1 or DOS/VS), try to keep all its major 110 devices on a separate channel from a channel handling the CMS system
residence volume or other user's disks. • Try to keep read-only mini disks
residence disk and source disks)
(for example, the CMS system
that are frequently accessed on IVMRELn may be VMREL5, VMREL6, and so forth, depending on the release
level.
164 IBM VM/370 Planning and System Generation Guide

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