HP XP7 Continuous Access Journal User Guide (TK911-96002)

• Restoring data to the secondary system is performed when the time stamp of the copied journal
is updated. The recommended interval between time stamps is one second.
Consider the following before setting the interval:
◦ I/O response time slows when time stamps are updating among multiple storage systems.
If you shorten the interval, more time stamps are issued, resulting in an I/O response time
that is slower yet.
◦ If the interval is lengthened, the amount of time that journal data can accumulate increases,
which results in an increased amount of data to be copied.
◦ None of the above is true during the initial copy or resynchronization. During these
operations, lengthening the interval between time stamps does not result in more
accumulated journal data, because data restoring takes place regardless of time stamp.
• The recommended method for executing RAID Manager commands is the in-band (host-based)
method. This prevents I/O response from deteriorating, which may occur with the out-of-band
(LAN-based) method.
• It is not possible to register a journal to multiple RAID Manager consistency groups.
Planning for previous models
You can pair XP7 volumes with P9500 and XP24000/XP20000 Disk Array volumes.
Observe the following:
• Configure a remote path between LDKC00 of the XP7 system and P9500 and
XP24000/XP20000 Disk Array. More than one P9500 or XP24000/XP20000 Disk Array
can be connected to XP7. Use configuration instructions in “Configuring primary and secondary
systems for Cnt Ac-J ” (page 55).
• Both systems must be set up as shown in the figure below.
Figure 4 Remote path between XP7 LDKC00 and P9500 or XP24000/XP20000 Disk Array
• When connecting XP7 with P9500 or XP24000/XP20000 Disk Array, set up the XP7 volume
using a CU:LDEV number between 00:00 to EF:FF.
• When connecting XP7 with P9500 or XP24000/XP20000 Disk Array, contact your HP
representative for information regarding supported microcode versions.
• When using the previous model storage system at the remote site, make sure the primary and
secondary system have unique serial numbers.
NOTE: When using RAID Manager (or Raidcom), the XP7 serial number requires a prefix
of "3".
Planning for previous models 29