IBM Flex System V7000 Expansion Enclosure 4939H29 Manual Do Utilizador
Códigos do produto
4939H29
Chapter 9. IBM Flex System V7000 Storage Node Copy Services
385
Draft Document for Review January 29, 2013 12:52 pm
8068ch09-Copy Servies.fm
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,
which is called an
be established on the volumes within one IBM Flex System V7000 Storage Node system,
which is called an
intra
-cluster relationship. The relationship can also be established between
two IBM Flex System V7000 Storage Nodes, or with an IBM Storwize V7000 storage systems
or an IBM SAN Volume Controller, which are called
or an IBM SAN Volume Controller, which are called
inter
-cluster relationships.
Usage of Remote Copy target volumes as Remote Copy source volumes is not allowed. A
FlashCopy target volume can be used as Remote Copy source volume and also as a Remote
Copy target volume.
FlashCopy target volume can be used as Remote Copy source volume and also as a Remote
Copy target volume.
Metro Mirror
Metro Mirror is a type of Remote Copy that creates a synchronous copy of data from a master
volume to an auxiliary volume. With synchronous copies, host applications write to the master
volume, but do not receive confirmation that the write operation has completed until the data
is written to the auxiliary volume. This action ensures that both volumes have identical data
when the copy completes. After the initial copy completes, the Metro Mirror function maintains
a fully synchronized copy of the source data at the target site at all times.
volume to an auxiliary volume. With synchronous copies, host applications write to the master
volume, but do not receive confirmation that the write operation has completed until the data
is written to the auxiliary volume. This action ensures that both volumes have identical data
when the copy completes. After the initial copy completes, the Metro Mirror function maintains
a fully synchronized copy of the source data at the target site at all times.
Figure 9-60 shows how a write to the master volume is mirrored to the cache of the auxiliary
volume before an acknowledgement of the write is sent back to the host that issued the write.
This process ensures that the auxiliary is synchronized in real time, if it is needed in a failover
situation.
volume before an acknowledgement of the write is sent back to the host that issued the write.
This process ensures that the auxiliary is synchronized in real time, if it is needed in a failover
situation.
Figure 9-60 Write on volume in a Metro Mirror relationship
The Metro Mirror function supports copy operations between volumes that are separated by
distances up to 300 km. For disaster recovery purposes, Metro Mirror provides the simplest
way to maintain an identical copy on both the primary and secondary volumes. However, as
with all synchronous copies over remote distances, there can be a performance impact to
host applications. This performance impact is related to the distance between primary and
secondary volumes and, depending on application requirements, its use might be limited
based on the distance between sites.
distances up to 300 km. For disaster recovery purposes, Metro Mirror provides the simplest
way to maintain an identical copy on both the primary and secondary volumes. However, as
with all synchronous copies over remote distances, there can be a performance impact to
host applications. This performance impact is related to the distance between primary and
secondary volumes and, depending on application requirements, its use might be limited
based on the distance between sites.
FlashCopy: Using target volumes as remote copy sources and target volumes for
FlashCopy requires Version 6.2.x or higher.
FlashCopy requires Version 6.2.x or higher.