IBM Storwize V7000, Introduction And Implementation Manual

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Chapter 2. Introduction to IBM Flex System V7000 Storage Node
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– Global Mirror:
Provides long distance asynchronous remote mirroring function up to approximately
8,000 km between sites. With Global Mirror, the host I/O completes locally and the
changed data is sent to the remote site later. This function is designed to maintain a
consistent recoverable copy of data at the remote site, which lags behind the local site.
Global Mirror can operate between multiple IBM Flex System V7000 Storage Node
systems and is only supported on FC host interfaces.
If both clusters are running 7.1.x or later, customers will be able to change between Metro
Mirror and Global Mirror (with or without change volumes) without the need to
re-synchronize. However, the relationship or consistency group needs to be in the stopped
state before changing.
򐂰 Data Migration (no licensing required for temporary usage):
With the benefit of external virtualization, IBM Flex System V7000 Storage Node allows
you to bring a system into your storage environment, and very quickly and easily migrate
data from existing storage systems to IBM Flex System V7000 Storage Node. For
licensing requirements, see “License requirements for migration” on page 50.
This function allows you to accomplish the following tasks:
– Move volumes non-disruptively onto a newly installed storage system
– Move volumes to rebalance a changed workload
– Migrate data from other back-end storage to IBM Flex System V7000 Storage Node
managed storage
򐂰 IBM System Storage Easy Tier (license included on the base license for IBM Flex System
V7000 Storage Node):
Provides a mechanism to seamlessly migrate hot spots to the most appropriate tier within
the IBM Flex System V7000 Storage Node solution. This migration could be to internal
drives within IBM Flex System V7000 Storage Node or to external storage systems that
are virtualized by IBM Flex System V7000 Storage Node.
򐂰 Real-time Compression:
Provides for data compression using the IBM Random-Access Compression Engine
(RACE), which can be performed on a per volume basis in real time on active primary
workloads. Real-time Compression can provide as much as a 50% compression rate for
data that is not already compressed. It can help with reducing the amount of capacity
needed for storage which can help with delaying further growth purchases. Real-time
Compression supports all storage that is attached to IBM Flex System V7000 Storage
Node whether internal, external, or external virtualized storage.
Note: If customers change from Global Mirror with change volumes to Metro Mirror,
then the Metro Mirror can still have a redundant change volume attached to it.
Note: The Easy Tier feature on compressed volumes previously was disabled, since
compression I/O looked random to Easy Tier; this prevented Easy Tier from detecting
hot extents correctly. EasyTier improvements are included in IBM Flex System V7000
Storage Node version 7.1.x or later to count only read I/Os and not count write I/Os on
compressed volumes.
Workload still needs to be considered for suitability to Easy Tier. If possible, move
uncompressed vdisks to a separate pool.