Page of GC20-1801-10 As Updated April 1, 1981 by TNL GN25-0837 VM/370 storage Requirements 504 bytes for a VMBLOK 64 bytes for the SEGTABLE 200 bytes for the PAGTABLE 680 bytes for the SWPTABLE 56 bytes for a virtual reader
56 bytes for a virtual printer
56 bytes for a virtual punch
168 bytes for three virtual disks 120 bytes for three virtual channels
56 bytes for a virtual machine console 120 bytes for three virtual control units 2080 bytes for each of the logged-on users defined
The number of virtual devices for a virtual machine cannot exceed the
value determined by (7FFFF/VDEVSIZE), where VDEVSIZE is the size of the VDEVBLOK. If a greater number of virtual devices is specified, results
may be undesirable. See the "specifying the Amount of virtual=Real Space" section for an
example of estimating storage requirements and determining the maximum
size of the virtual=real area.
Reducing the Size of the CP Nucleus
Support for the 3340, 3704, 3705, 3066, 3850, and 3270 increases the
size of the CP nucleus. 3340 support is handled by the module DMKTRK. The 3704/3705 is primarily handled by the module DMKRNH. 3850 Mass storage system support is provided in module DMKSSS. The graphic device
support for locally attached terminals is handled by the module DMKGRF while the 3270 support is handled by the DMKRGA, DMKRGB, and DMKBSC modules. Each of these modules occupies space in the system
nucleus.
This nucleus area can be reclaimed by deleting DMKTRK, DMKRNH, DMKMSS, DMKGRF, DMKRGA, DMKRGB, and DMKBSC from the system loadlist EXEC file. caution should be exercised before deleting them from the loadlist. If you generate a system which includes 3340 disks in the IIO configuration, you cannot delete the module DMKTRK. If you generate any
type of locally attached graphic device in the DMKRIO assemble file, you
cannot delete the module DMKGRF. Or, if you generate remote 32705 in
the DMKRIO assemble file, you cannot delete the DMKRGA, DMKRGB, and DMKBSC modules. Module DMKSSS cannot be deleted if you are using a 3850. In addition, if you generate the 3704/3705 in the DMKRIO assemble
file, you cannot delete the DMKRNH module.
The following names are undefined during the VMFLOAD procedure if DMKTRK is deleted from the loadlist: DMKTRKIN DMKTRKFP DMKTRKVA The followinq names are undefined during the VMFLOAD procedure if DMKGRF and DMKRNH are deleted from the loadlist:
DMKGRFEN
DMKGRFIC
DMKGRFIN
DMKRNHCT
DMKRNHIC
DMKRNHIN
DMKRNHND
DMKRNHTR Part 1. Planning for System Generation 89

-I. ----- --.1:""--- .•. __ . -1 ---- _ .. --- ---" VM/370 Storage Requirements
The followinq names are undefined during the VMFLOAD procedure if
DMKBSC, DMKRGA, and DMKRGB are deleted from the loadlist: DMKBSCER DMKRGBEN
DMKRGBIC
DMKRGAIN
The following names are undefined during the VMFLOAD procedure if DMKSSS is deleted from the loadlist: DMKSSSHV DMKSSSAS 1)MKSSSMQ DMKSSSL 1 DMKSSSI1 DMKSSSL2 DMKSSSEN DMKSSSL3 DMKSSSVA DMKSSSDE If you generate your system without the V=R option, the module DMKVSC can be deleted from the loadlist with no undefined symbols.
Direct Access Storage Requirements for CP Fiqure 15 shows how much DASD soace CP requires by followinq paragraphs describe in detail how you determine the amount of DASD space CP requires for the nucleus, error recording, warm start
data, checkpoint data, directory, saved systems data, paging, and
spoolinq space. CP Nucleus
Error Recording 1 Warm Start Checkpoint Start Directory Sa ved Syste ms
pagin g Space Spoolinq Space Total System
2 2319 varies
2
1
2
2
varies
32 50 93 cyl varies
2
1
1
2
varies
18 30 57 cyl varies
2
1
3
2
varies 40 varies
2
1
3
2
varies 40 70 53 cyl 123 cyl
Fiqure 15. DASD Space Requirements by DASD Type CP NUCLEUS DASD REQUIREMENTS varies
2
1
1
2
varies 10 15
33 cyl
The CP nucleus (without a virtual=real area) currently requires about
115 pages of disk space for resident and pageable functions.
To determine the number of cylinders required for the CP nucleus,
refer to the load map produced during system generation. One DASD page
is required for each page of fixed and pageable nucleus (for a CP nucleus without a virtual=real area). The calculations for the amount
of DASD space needed for a CP nucleus with a virtual=real area are in the" Specifying a virt ual=Real Machine" section.
lThe default is 2 cylinders but up to 9 cylinders may be specified via
the SYSERR operand of the SYSRES macro.
2These figures do not include space for the nucleus or saved systems. 90 IBM VM/370 planning and System Generation Guide