HP StorageWorks XP Disk Array Mainframe Host Attachment and Operations Guide XP24000, XP20000 (A5951 - 96151, September 2007)

the event of a disaster or system failure, the secondary copy of data can be rapidly invoked to allow
recovery with a very high level of data integrity. Universal Replicator for Mainframe can also be used
for data duplication and migration tasks.
Universal Replicator for Mainframe represents a unique and outstanding disaster recovery solution
for large amounts of data which span multiple volumes. The Universal Replicator for Mainframe
group-based update sequence consistency solution enables fast and accurate database recovery,
even after a “rolling” disaster, without the need for time-consuming data recovery procedures. The
journal groups (volume groups) at the secondary site can be recovered with full update sequence
consistency, but the updates will be behind the primary site due to the asynchronous remote copy
operations. Universal Replicator for Mainframe provides update sequence consistency for user-defined
journal groups (e.g., large databases) as well as protection for write-dependent applications in the
event of a disaster.
Compatible XRC
The Compatible XRC asynchronous remote copy feature of the storage system is functionally compatible
with IBM Extended Remote Copy (XRC, XRC3). Compatible XRC provides asynchronous remote copy
operations for maintaining duplicate copies of mainframe data for data backup purposes. Once
established, operations continue unattended to provide continuous data backup. Compatible XRC
operations are non-disruptive and allow the primary Compatible XRC volumes to remain online to the
host(s) for both read and write I/O operations. For Compatible XRC operations, there is no distance
limit between the primary and remote storage systems. Compatible XRCis also compatible with the
DFSMS data mover that is common to the XRC environment.
Compatible XRC operations are performed in the same manner as XRC operations. The user issues
standard XRC TSO commands from the mainframe host system directly to the storage system. For
enhanced usability, Compatible XRC settings can now be configured using the XRC remote console
(XP Remote Web Console) software. Compatible XRC can be used as an alternative to TrueCopy for
Mainframe for mainframe data backup and disaster recovery planning. However, Compatible XRC
requires host processor resources that may be significant for volumes with high-write activity. The Data
Mover utility may run in either the primary host or the optional remote host.
XP for Data Exchange
XP for Data Exchange enables the user to transfer data. Mainframe platforms use ExSA and FICON
channels, and open-system platforms use FICON channels. XP for Data Exchange enables high-speed
data transfer without requiring network communication links or tape. Data transfer is performed over
the XP for Data Exchange volumes, which are shared devices that appear to the mainframe host as
3390 LVIs and to the open-system host as OPEN LUs. To provide the greatest platform flexibility for
data transfer, the volumes are accessed from the open-system host using SCSI raw device mode.
XP for Data Exchange allows the open-system host to read from and write to mainframe sequential
datasets using the volumes. The volumes must be formatted as 3390-3A/B/C LVIs. The -A LVIs can
be used for open-to-mainframe and/or mainframe-to-open XP for Data Exchange, the -B LVIs are used
for mainframe-to-open XP for Data Exchange, and the -C LVIs are used for open-to-mainframe XP for
Data Exchange. XP for Data Exchange also supports OPEN-x-FX devices to provide open-to-open XP
for Data Exchange operations for storage systems.
The software enables the open-system host to read from and write to individual mainframe datasets.
The software is installed on the open-system host and includes the File Conversion Utility (FCU) and
the File Access Library (FAL). FCU allows the user to set up and perform file conversion operations
between mainframe sequential datasets and open-system flat files. The FAL is a library of C-language
functions that allows open-system programmers to read from and write to mainframe sequential datasets
on the volumes.
XP Disk Array Mainframe Host Attachment and Operations Guide 15