DEFLVE S TOR T\G ErA S ]
{
nnnnnK} nnM redefines the size of the virtual storage for the virtual
machine as nnnnnK (where K represents 1024 bytes) or nnM (where M represents 1,048,576 bytes). The value specified
becomes the new virtual storage size. Sizes must be in 4K
increments and are limited by the maximum value in the VM/370 directory entry. The minimum size you can specify is 8K. All entries not specified in a 4K increment are rounded up to the next 4K boundary. Changinq the virtual storage size
(increasing or decreasing) causes a virtual system reset and
clears all virtual storage to binary zeros.
1. When you alter the configuration or channel operatinq mode of your
virtJal machine via the DEFINE command, the changes are temporary
and are in effect for the current terminal session only.
2. If either storaqe or channel operating mode is altered, the virtual maGhine is immediately reset and the IPL procedure must be performed again.
3. If storaqe is redefined, any pages that have been locked via the LOCK command become unlocked.
4. If your vi:.tual machine is operating in the basic control mode OFF), virtual addresses specified in vaddr, vaddr1, and
vaddr2 can be no higher than 5FF (channels 0 through 5). If it is
operatinq in extended control mode {ECMODE ONt, all addresses
throuqh FFF are valid.
5. Use caution in defining the hexadecimal addresses of virtual (cuu) in DEFINE statements in order to avoid a usage caused by control unit I/O interface protocol. The foll)wing is an example of a virtual machine's DEFINE statements
that can cause operational conflict: 3211 as 102
define qraf 103 3270
The virtual addresses of both the 3211 printer and the 3270 terminal indicate the use of the same Ghannel (1) and control unit (0). BV definition, the devices are virtual and therefore share
one 1irtual control unit in CP. A real 3211 printer operates on a
nonshared subchannel, and the real 3270 console is designed for
shared subchannel operations. Both of these real devices are mapped to the same virtual control unit. Thus, subsequent
processing of a channel program involving these devices can result
in a hunq or busy condition (caused by a Gonflict in
real-to-virtual 1/0 processing). Therefore, when defining devices,
make sure the devices are defined. (and separated; within their own
control unit ranqe and not shared with other devices. CD r.ommand Feference for General Users

DEFINE
Pesponses arp- qenerated to confirm that the aesired configuration change
has taken These responses do not appear on your terminal if you have issued the CP SET IMSG OFF command line.
type vaddr where the possible values for type are: TY2§ Dl\SD TAPE LINE
RDR PRT PiJN G"qAF CONS CTC/\ MSC CHANNELS !1§§:nirrg Direct access storaqe device/3330V(virtual volumes)
Magnetic tape Communication line Card reader
tine printer Card punch
Graphics device Console Channel-to-channel adapter Storaqe Control = {SEL} B,.,X is the channel mode of operation for the virtual machine. This response applies to all channels except channel 0 (always a byte
multiplexer channel) and any channel that has a virtual or real adapter (always a selector channel). STORAGE = {nnn.nnK} nnM verifies the new storage size of your virtual machine. The minimum
storaqe you may specify is 8K.
section 5. Format of CP Commands 65