IBM Storwize V7000, Introduction And Implementation Manual

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IBM Flex System V7000 Storage Node Introduction and Implementation Guide
– Multitarget FlashCopy:
IBM Flex System V7000 Storage Node supports copying of up to 256 target volumes
from a single source volume. Each copy is managed by a unique mapping and, in
general, each mapping acts independently and is not affected by other mappings
sharing the source volume.
– Cascaded FlashCopy:
This function is used to create copies of copies and supports full, incremental, or
nocopy operations.
– Reverse FlashCopy:
This function allows data from an earlier point-in-time copy to be restored with minimal
disruption to the host.
– FlashCopy nocopy with thin provisioning:
This function provides a combination of using thin-provisioned volumes and FlashCopy
together to help reduce disk space requirements when making copies. There are two
variations of this option:
• Space-efficient source and target with background copy:
Copies only the allocated space.
• Space-efficient target with no background copy:
Copies only the space used for changes between the source and target and is
generally referred to as “snapshots”.
This function can be used with multi-target, cascaded, and incremental FlashCopy.
– Consistency groups:
Consistency groups address the issue where application data is on multiple volumes.
By placing the FlashCopy relationships into a consistency group, commands can be
issued against all of the volumes in the group. This action enables a consistent
point-in-time copy of all of the data, even though it might be on a physically
separate volume.
FlashCopy mappings can be members of a consistency group, or they can be operated
in a stand-alone manner, that is, not as part of a consistency group. FlashCopy
commands can be issued to a FlashCopy consistency group, which affects all
FlashCopy mappings in the consistency group, or to a single FlashCopy mapping if it is
not part of a defined FlashCopy consistency group.
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Remote Copy feature:
Remote Copy is an optional licensed feature that is based on the number of enclosures
that are being used at the configuration location. See “Remote Copy (Advanced Copy
Services: Metro Mirror / Global Mirror)” on page 48 for licensing details. Remote Copy
provides for the capability to perform either Metro mirror or Global Mirror operations:
– Metro Mirror:
Provides a synchronous remote mirroring function up to approximately 300 km
between sites. As the host I/O only completes after the data is cached at both
locations, performance requirements might limit the practical distance. Metro Mirror is
designed to provide fully synchronized copies at both sites with zero data loss after the
initial copy is completed.
Metro Mirror can operate between multiple IBM Flex System V7000 Storage Node
systems and is only supported on either FC or FCoE host interfaces.