Journal volume, The number of journal volumes, Specifications of journal volumes – HP StorageWorks XP Remote Web Console Software User Manual
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duplicated. See
for further information on LU requirements and
support.
IMPORTANT:
If you connect the IBM OS installed host and the Fujitsu OS installed host to a same
storage system, call HP technical support when creating a Universal Replicator for Mainframe pair
by using volumes that are connected by IBM OS installed host.
Journal Volume
When Universal Replicator for Mainframe is used, updates to primary data volumes can be stored
in other volumes, which are called journal volumes. The updates (which are sometimes referred to
as update data) that will be stored in journal volumes are called journal data.
Because journal data will be stored in journal volumes, you can perform and manage highly
reliable remote copy operations without suspension of remote copy operations. For example, even
if a communication path between the primary storage system and the secondary storage system
fails temporarily, remote copy operations can continue after the communication path is recovered.
If data transfer from hosts to the primary storage system is temporarily faster than data transfer
between the primary storage system and the secondary storage system, remote copy operations
between the primary storage system and the secondary storage system can continue. Because
journal volumes can contain a lot more update data than the cache memory can contain, remote
copy operations can continue if data transfer from hosts to the primary storage system is faster for
a relatively long period of time than data transfer between the primary storage system and the
secondary storage system.
The Number of Journal Volumes
One journal group can contain up to 64 journal volumes. Each of the journal volumes can have
different volume sizes and different RAID configurations. Journal data will be stored sequentially
and separately into each journal volume in the same journal group.
Specifications of Journal Volumes
•
Types of LUs.
DKU emulation types that are allowed for journal volumes are shown in
Table 2 Emulation Types for Journal Volumes
Supported Emulation Types
Emulation Category
◦ OPEN-V
◦ All mainframe volumes that can be used with the XP disk array
NOTE:
Status of mainframe volumes cannot be referenced.
DKU (drive)
•
Volumes and their capacity.
You can use VLL volumes for journal volumes.
Journal volumes in the same journal group can be of different capacity. A master journal
volume and the corresponding restore journal volume can be of different capacity.
A journal volume consists of two areas: one area is used for storing journal data, and the
other area is used for storing metadata for remote copy.
•
RAID configuration.
Journal volumes support all RAID configurations that are supported by the XP disk array.
Journal volumes also support all physical volumes that are supported by the XP disk array.
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About Universal Replicator for Mainframe Operations