IBM DS8900F, Введение и руководство по планированию, Страница: 57 / 172

Copy Services
Copy Services functions can help you implement storage solutions to keep your business running 24
hours a day, 7 days a week. Copy Services include a set of disaster recovery, data migration, and data
duplication functions.
The storage system supports Copy Service functions that contribute to the protection of your data. These
functions are also supported on the IBM TotalStorage
™
Enterprise Storage Server
®
.
Notes:
• If you are creating paths between an older release of the DS8000 (Release 5.1 or earlier), which
supports only 4-port host adapters, and a newer release of the DS8000 (Release 6.0 or later), which
supports 8-port host adapters, the paths connect only to the lower four ports on the newer storage
system.
• If you are creating paths from a model 993 4-port host adapter to a previous release DS8000 (Release
6.0 or later), which supports 8-port host adapters, you can only connect the lower four ports of the 8-
port host adapter.
• The maximum number of FlashCopy relationships that are allowed on a volume is 65534. If that
number is exceeded, the FlashCopy operation fails.
• The size limit for volumes or extents in a Copy Service relationship is 2 TB.
• Thin provisioning functions in open-system environments are supported for the following Copy Services
functions:
– FlashCopy relationships
– Global Mirror relationships if 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 an ESE
volume or standard volume.
• PPRC supports any intermix of T10-protected or standard volumes. FlashCopy does not support
intermix.
• PPRC supports copying from standard volumes to ESE volumes, or ESE volumes to Standard volumes,
to allow migration with PPRC failover when both source and target volumes are on a DS8000 version
8.2 or higher.
The following Copy Services functions are available as optional features:
• Point-in-time copy, which includes IBM FlashCopy.
The FlashCopy function allows you to make point-in-time, full volume copies of data so that the copies
are immediately available for read or write access. In IBM Z environments, you can also use the
FlashCopy function to perform data set level copies of your data.
• Remote mirror and copy, which includes the following functions:
– Metro Mirror
Metro Mirror provides real-time mirroring of logical volumes between two storage system 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.
– Global Copy
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.
– Global Mirror
Global Mirror is a long-distance remote copy function across two sites by using asynchronous
technology. Global Mirror processing is designed to provide support for 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.
Chapter 3. Data management features 43