Hitachi TrueCopy for IBM z/OS User and Reference Guide (T5211-96001, June 2007)

About TrueCopy for z/OS Operations 2-15
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
Initial Copy Operation
The initial copy operation synchronizes the M-VOL and R-VOL independently of
host I/O processes. The initial copy operation is the same for TCz Synchronous
and Asynchronous pairs. A TCz initial copy operation takes place when you add
a new pair or resynchronize a suspended pair. When a new pair is established,
the entire contents of the M-VOL are copied to the R-VOL by track, including
the VTOC (volume table of contents) but not including the diagnostic and
unassigned alternate tracks. If None is selected, the user is responsible for
ensuring that the M-VOL and R-VOL are already identical. The MCU cannot
verify the contents of the volumes. When a suspended pair is resynchronized,
only the VOLSER and out-of-sync tracks (updated by write I/Os while the pair
was suspended) are copied to the R-VOL.
For additional flexibility, TCz provides the following options for the initial copy
operation:
• The number of tracks option allows you to specify how many tracks are
copied simultaneously by the TCz initial copy operation when
adding/resynchronizing a TCz pair. This option can be specified using the TCz
software and the CESTPAIR TSO command (PACE parameter).
• The Initial Copy Priority option allows you to specify the order in which the
initial copy operations are performed when adding/resynchronizing multiple
TCz pairs. This option can only be specified using the TCz software (not
PPRC).
• The Maximum Initial Copy Activities option allows you to specify the
maximum number of concurrent initial copy operations that each MCU can
perform (not pair-specific). This option can only be specified using the TCz
software (not PPRC).