HP StorageWorks XP Remote Web Console Software - Manual (Page 64)

will abort the TrueCopy for Mainframe initial copy operation if the track format for both the M-VOL
and R-VOL does not meet the following requirements.
•
The TrueCopy for Mainframe 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 Mainframe requires a one-to-one relationship between the volumes of the pairs. A
volume can only be assigned to one TrueCopy for Mainframe pair at a time. TrueCopy for
Mainframe 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 TrueCopy for Mainframe 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 TrueCopy for Mainframe R-VOLs, and use TrueCopy for Mainframe
Asynchronous to ensure update sequence consistency across the R-VOLs at the remote site.
Duplicate VOLSER
The TrueCopy for Mainframe initial copy operation copies the VOLSER of the M-VOL to the R-VOL,
if the No Copy initial copy option is not selected. For this reason, the M-VOL and R-VOL of a
TrueCopy for Mainframe pair must have the same VOLSER. Since the host OS does not allow
duplicate VOLSERs, the host system administrator must take precautions to prevent system problems
related to duplicate VOLSERs. For example, the TrueCopy for Mainframe R-VOLs must be defined
in the system generation so they do not come online automatically (see CAUTION below).
CAUTION: If the volumes which will become TrueCopy for Mainframe R-VOLs are physically
attached to the same system images as the production volumes which will become the TrueCopy
for Mainframe M-VOLs, the following problems can occur:
•
When a TrueCopy for Mainframe pair is established using the TSO CESTPAIR command, the
secondary volume might be online (PPRC allows this; TrueCopy for Mainframe does not*).
This could produce a duplex secondary online to a host image, the results of which are not
predictable.
•
When a TrueCopy for Mainframe pair is released, the old secondary volume is usually offline.
If a host image is IPL'd, the operator will be offered both volumes and asked which volume
should be left offline − the old duplicate volser message. This can be confusing and is prone
to error. To avoid duplication of VOLSER, first you must identify the volumes that will not be
accessed by the host system. Next, you must perform CHP OFF or some other operation to
ensure that the volumes are inaccessible. After that, when performing IPL, you must perform
LOAD CLEAR.
To avoid these problems, HP strongly recommends that the user specify OFFLINE=YES if the
secondary volumes are to be generated in the production host's IOCP and system generation.
If you cannot create a pair because the TrueCopy for Mainframe R-VOL is online with hosts, all
paths must be offline from all hosts. If you cannot identify the hosts that are online, contact your
HP account team. You can obtain the information about online paths from SSBLOG of SVP.
Logical Volume Image (LVI)
TrueCopy for Mainframe supports all basic mainframe LVIs which can be configured on the HP
disk array (for example, 3390-3, -3R, -9, -L). TrueCopy for Mainframe does not support multiplatform
64 Preparing for TrueCopy for Mainframe Operations