IBM TotalStorage DS6000 Series Redbooks page 120

A more detailed discussion of the concept of
Consistency Group operation is in 6.2.5, "What is Consistency Group?" on page 105.
Important: Consistency Group FlashCopy can create host-based consistent copies; they
are not application-based consistent copies. The copies have
consistency. This means that if you suddenly power off your server without stopping your
applications and without destaging the data in the file cache, the data in the file cache may
be lost and you may need recovery procedures to restart your applications. To start your
system with Consistency Group FlashCopy target volumes, you may need the same
operations as the crash recovery.
For example, If the Consistency Group source volumes are used with a journaled file
system (like AIX JFS) and the source LUNs are not unmounted before running FlashCopy,
it is likely that fsck will have to be run on the target volumes.
Note: Consistency Group FlashCopy is only available through the use of CLI commands
and not the DS Storage Manager GUI at the current time.
Establish FlashCopy on existing Remote Mirror and Copy primary
This option allows you to establish a FlashCopy relationship where the target is also a remote
mirror primary volume. This enables you to create full or incremental point-in-time copies at a
local site and then use remote mirroring commands to copy the data to the remote site. We
explain the functions of Remote Mirror and Copy in 6.2.3, "Remote Mirror and Copy
(Peer-to-Peer Remote Copy)" on page 97.
Figure 6-6 Establish FlashCopy on existing Remote Mirror and Copy primary
Note: You cannot FlashCopy from a source to a target, where the target is also a Global
Mirror primary volume.
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DS6000 Series: Concepts and Architecture
FlashCopy
Source Volume
FlashCopy
Target Volume
PPRC relation
PPRC
Primary Volume
data consistency
and how to manage the
power-fail
FlashCopy to
PPRC Primary
Volume
PPRC
Secondary Volume
crash
or level