IBM DS8700, Введение и руководство по планированию

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release of the DS8000 (Release 6.0 or later), which supports 8-port host
adaptors, the paths should connect only to the lower four ports on the
newer storage unit.
v
The maximum number of FlashCopy relationships allowed on a volume
is 65534. If that number is exceeded, the FlashCopy operation fails.
v The size limit for volumes or extents in a Copy Service relationship is 2
TB.
v
Thin provisioning functions in open-system environments are supported
for the following Copy Services functions:
– FlashCopy relationships
– Global Mirror relationships provided that the Global Copy A and B
volumes are Extent Space Efficient (ESE) volumes. The FlashCopy
target volume (Volume C) in the Global Mirror relationship can be a
ESE volume, Target Space Efficient (TSE) volume, or standard volume.
v
PPRC supports any intermix of T10-protected or standard volumes.
FlashCopy does not support intermix.
The following Copy Services functions are available as optional features:
v Point-in-time copy, which includes IBM System Storage FlashCopy and
Space-Efficient FlashCopy
The FlashCopy function enables you to make point-in-time, full volume copies
of data, so that the copies are immediately available for read or write access. In
System z environments, you can also use the FlashCopy function to perform
data set level copies of your data.
v
Remote mirror and copy, which includes the following functions:
–
IBM System Storage Metro Mirror (previously known as Synchronous PPRC)
Metro Mirror provides real-time mirroring of logical volumes between two
DS8000 storage units that can be located up to 300 km from each other. It is a
synchronous copy solution where write operations are completed on both
copies (local and remote site) before they are considered to be done.
– IBM System Storage Global Copy (previously known as PPRC Extended
Distance)
Global Copy is a nonsynchronous long-distance copy function where
incremental updates are sent from the local to the remote site on a periodic
basis.
– IBM System Storage Global Mirror (previously known as Asynchronous
PPRC)
Global Mirror is a long-distance remote copy function across two sites using
asynchronous technology. Global Mirror processing is designed to provide
support for virtually unlimited distance between the local and remote sites,
with the distance typically limited only by the capabilities of the network and
the channel extension technology.
– IBM System Storage Metro/Global Mirror (a combination of Metro Mirror
and Global Mirror)
Metro/Global Mirror is a three-site remote copy solution, which uses
synchronous replication to mirror data between a local site and an
intermediate site, and asynchronous replication to mirror data from an
intermediate site to a remote site.
v Remote mirror and copy for System z environments, which includes z/OS
Global Mirror
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Introduction and Planning Guide
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