IBM DS8000 - ADDITIONAL INFORMATION, Руководство пользователя, Страница: 136 / 250

– Failover and failback
– Copy Services functions across a 2105 and 2107
– Copy Services functions with i5/OS
v
In addition, the following example Copy Services tasks are included at the end
of the chapter:
– Creating remote FlashCopy transactions (known as inband FlashCopy on the
ESS 2105)
– Adding a Copy Services 2105 domain to a storage complex
– Creating a Metro Mirror volume pair between a 2107 and a 2105
FlashCopy
The FlashCopy function enables you to make point-in-time, full volume copies of
data, with the copies immediately available for read or write access. You can use
the copy with standard backup tools that are available in your environment to
create backup copies on tape.
FlashCopy creates a copy of a source volume on the target volume. This copy is
called a point-in-time copy. When you initiate a FlashCopy operation, a FlashCopy
relationship is created between a source volume and target volume. A FlashCopy
relationship is a
″
mapping
″
of the FlashCopy source volume and a FlashCopy
target volume. This mapping allows a point-in-time copy of that source volume to
be copied to the associated target volume. The FlashCopy relationship exists
between this volume pair from the time that you initiate a FlashCopy operation
until the storage unit copies all data from the source volume to the target volume
or you delete the FlashCopy relationship, if it is a persistent FlashCopy.
When the data is physically copied, a background process copies tracks from the
source volume to the target volume. The amount of time that it takes to complete
the background copy depends on the following criteria:
v
The amount of data being copied
v The number of background copy processes that are occurring
v
The other activities that are occurring on the DS8000
FlashCopy supports the following copy options:
Consistency groups
Creates a consistent point-in-time copy of multiple volumes, with
negligible host impact. You can enable FlashCopy consistency groups from
the command-line interface (DS CLI).
Change recording
Activates the change recording function on the volume pair that is
participating in a FlashCopy relationship. This enables a subsequent refresh
to the target volume.
Establish FlashCopy on existing Metro Mirror source
Allows you to establish a FlashCopy relationship where the target volume
is also the source of an existing remote mirror and copy source 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.
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DS8000 User’s Guide