HP StorageWorks XP24000 Continuous Access Journal Software User and Reference Guide, v01 (T5278-96001, June 2007)

Continuous Access Journal Software
TheRemoteWeb Co
nsole Java app lication program product includes Continuous Access Journal for
the
storage sys
tem. The storage system Remote Web Console software communicates with the SVP of
each storage sy
stem via defined TCP/IP connections. For further information on Remote Web Console
operations, see the H P StorageWorks XP24000 Remote Web Console User’s Guide or contact your H P
service representativ e.
TheRemoteWeb C
onsole
computer at the primary site must be attached to the primary storage system.
You should a lso attach a Remote Web Console comp uter at the seco n dary s ite to all secondary storage
systems. Having a Remote Web Console c omputer at the sec ondary site enables you to change the
Continuous Access Journal parameter for the secondar y storage system and access the Continuous
Access Journal secondary data volume (for example, for ma intenance of media). If you need to perform
Continuous A
ccess Journal operations in the reverse d irection from the remote site to the p rimary site
(for example, for disaster recovery), the storage system Continuous Access Journal simplifies and
expedites this process.
Note: If the
storage system Remote Web Console remote console computer is not installed, contact your
HP
service r
epresentative for information on Continuous Access Journal configuration services.
Logical Disk Controllers
CUs (control units) in the storage system are divided into groups of 255 CUs. Each group of CUs is
controlled by a virtual storage system that log ically exists in the storage system (logical storage system).
This virtual storage subsystem is called a logical DKC or an LD KC (Logical disk controller). There are two
LDKCs in the storage system, and number 00 or 0 1 is assigned to each LDKC.
Each LDKC controls 255 CUs. However, the number of CUs that can be used for storage system program
products is up to 255. Therefore, the maximum number of volumes that ca n be used for storage system
program products is 130,560 (65,280 volumes for an LD KC).
Main and
Remote Control Units (Primary Storage System s and Secondary
Storage Systems)
The main
control unit (primary storage system) a nd remote control u nit (secondary storage system)
control Continuous Access Journal operations:
• The primar y storage system is the control unit in the primary storage system which controls the
primary data volume of the Continuous Access Journal pairs and master journal volume. The
Remote
We b Console remote console computer must be LAN-at tached to the primary storage
system. The primary storage system communicates with the secondary storage system via the
dedicated remote copy connections. The primary storage system controls the host I/O operations
to the Continuous Access Journal primary data volume and the journal obtain operation of the
master journal volume, as well as the Continuous Access Journal initial copy and update copy
oper
ations between the primary data volumes and the secondary da ta volumes.
• The secondar y storage system is the control unit in the secondary storage system which controls
the
secondary da ta volume of the Continuous Access Jou rnal pairs and restore journal volume.
The secondary storage system controls copying journals and restoring journals to secondary data
vol
umes. The secondar y storage system assists in managing the Continuous Access Journal
pai
rstatusand configuration (for example, rejects write I/Os to the Continuous Access Journal
secondary data volumes) . The secondary storage system issues the read journal com mand
to theprimary storagesystemand executes copyingjournals. ThesecondaryRemoteWeb
Co
nsole computer should be connected to the secondary storage systems at the secondary site
on a
separate L A N. The secondary storage systems should also be attached to a host system to
allow sense information to b e reported in case of a problem with a secondary data volume or
secondary storage system and to provide disaster recovery capabilities.
The storage system can function simultaneously as a primary storage system for one or more primary
data volumes and as an secondary storage system for one or more secondary data volumes, provided
the
remote c opy connections and Fibre Cha nnel interface ports are properly configured. Continuous
XP24000 Continuous Access Journal Software User a nd Reference Guide
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