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

Preparing for TrueCopy for z/OS Operations 3-5
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
Requirements and Restrictions
TrueCopy for z/OS has the following requirements and restrictions:
• Track format
• One-to-one volume copy operations
• Duplicate VOLSER (Volume Serial Number)
• Logical volume image (LVI)
• Accessing TCz M-VOLs and R-VOLs
• Cache, NVS, and DASD fast write
• Consistency groups
• Restrictions on volumes
Track Format
TrueCopy for z/OS has the following disk track format requirements which
must be ensured by the user. TCz cannot detect exceptions to these
requirements. The MCU will abort the TCz initial copy operation if the track
format for both the M-VOL and R-VOL does not meet the following
requirements.
• The TCz M-VOL and R-VOL must have the same track format.
• Record zero (R0) must be standard format, with key length of zero and data
length of eight. The MCU will abort the initial copy operation if R0 is not
standard format.
• The CCHH (logical cylinder address and logical head address) of R0 must be
identical to the physical cylinder address and physical head address of the
track.
• The CCHH of each user record in a track must be unique.
One-to-One Volume Copy Operations
TrueCopy for z/OS requires a one-to-one relationship between the volumes of
the pairs. A volume can only be assigned to one TCz pair at a time. TCz does
not support operations in which one M-VOL is copied to more than one R-VOL,
or more than one M-VOL is copied to one R-VOL. Since TCz pairs are created
on volumes rather than datasets, multivolume datasets require special
attention. For complete duplication and recovery of multivolume datasets,
make sure that all volumes of a multivolume dataset are copied to TCz R-
VOLs, and use TCzA to ensure update sequence consistency across the R-VOLs
at the remote site.