IBM Storwize V7000, Introduction And Implementation Manual

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IBM Flex System V7000 Storage Node Introduction and Implementation Guide
9.3.3 Remote Copy planning
Before you use Remote Copy, you need to plan for its usage.
General guidelines for Remote Copy
General guidelines for Remote Copy include the following items:
򐂰 A partnership is allowed between a mix of up to four IBM Flex System V7000 Storage
Node, IBM Flex System V7000 Storage Node, or IBM SAN Volume Controller systems.
The partnership must be defined on all partnered members to make it fully functional.
򐂰 The two volumes in a relationship must be the same size.
򐂰
The Remote Copy relationship can be established on the volumes within one IBM Flex
System V7000 Storage Node system or in different IBM Flex System V7000 Storage Node
systems. When the two volumes are in the same cluster, they must be in the same I/O
group.
򐂰 You cannot use Remote Copy target volumes as Remote Copy source volumes. A
FlashCopy target volume can be used as Remote Copy source volume, as of Version
6.2.0. There are additional restrictions outlined in Table 9-5 on page 417.
򐂰 The Metro Mirror function supports copy operations between volumes that are separated
by distances up to 300 km. Metro Mirroring is supported over either an FC or FCoE/FC
SAN infrastructure.
򐂰 Global Mirroring function supports copy operations between volumes that are separated
by distances over 300 km. Global Mirroring is only supported over an FC SAN
infrastructure.
At this time no remote mirroring functions are supported over the iSCSI fabric. Consult
IBM System Storage Interoperation Center (SSIC) for supported configurations at:
http://www-03.ibm.com/systems/support/storage/ssic/interoperability.wss
򐂰 One Remote Copy relationship can only belong to one consistency group.
򐂰
All relationships in a consistency group must have matching primary and secondary
clusters, which are sometimes referred to as master and auxiliary clusters. All
relationships in a consistency group must also have the same copy direction and state.
򐂰 Metro Mirror and Global Mirror relationships cannot belong to the same
consistency group.
򐂰
To manage multiple Remote Copy relationships as one entity, relationships can be made
part of a Remote Copy consistency group, which ensures data consistency across
multiple Remote Copy relationships and provides ease of management.
򐂰 IBM Flex System V7000 Storage Node implements flexible resynchronization support,
enabling it to resynchronize volume pairs that have experienced write I/Os to both disks,
and to resynchronize only those regions that are known to have changed.