z/VM: CP Commands and Utilities Reference - z/VM - IBM

DUPLEX
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Pace:
Notes:
DUPlex
(1)
PAce
Authorization
Purpose
Operands
prdev
nnn
ON
SECDev
Privilege Class: B
srdev
OFF
SECVolid volid
SUSpend PRImary
SECondary
COpy
RESynch
NOCopy
Pace
Pace
SECVolid
volid
1 The default pacing value is the number of tracks per cylinder for the device types involved.
Use the DUPLEX command to perform duplex control operations (such as
establishing or discontinuing a duplex pair) on devices attached to 3990 Model 3
and 3990 Model 6 subsystems.
This duplexing of devices makes use of the Dual Copy function, which allows two
devices attached to the same 3990 Model 3 or 6 storage subsystem to operate in
duplex mode. All data written to the primary device is automatically written to the
specified secondary (copy) device. Thus, the host is relieved of performing this task
when a duplicate copy of one or more DASD is desired.
prdev
is the real device number of the primary volume in the duplex pair.
DUPLEX
ON srdev
ON SECDev srdev
ON indicates that a duplex pair is to be established or re-established with the
volumes specified.
SECDev is an optional keyword which may be used to clarify the fact that the
real device number specified is the secondary device of a duplex pair.
The srdev is the real device number of the secondary volume which will be in
the duplex pair when the command completes. This real device number
specifies either:
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Chapter 2. CP Commands 413