IBM Flex System V7000 Expansion Enclosure 4939H29 ユーザーズマニュアル

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Draft Document for Review January 29, 2013 12:52 pm
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IBM Flex System V7000 Storage Node Introduction and Implementation Guide
Customers who wish to use the global mirror capability with Flex System V7000 on a low 
bandwidth link between sites can do so with the use of the low bandwidth remote mirroring. 
This capability provides options to help administrators balance network bandwidth 
requirements and RPO times for applications, helping reduce operation costs for disaster 
recovery solutions. Remote mirroring supports higher RPO times by allowing the data at the 
disaster recovery site to get further out of sync with the production site if the communication 
link limits replication, and then approaches synchronicity again when the link is not as busy. 
This low bandwidth remote mirroring uses space-efficient FlashCopy targets as sources in 
remote copy relationships to increase the time allowed to complete a remote copy data cycle.
Refer to 9.3, “Remote Copy” on page 380 for more information about the Remote Copy 
services.
2.6.3  Remote Copy licensing
To authorize use of remote copy capabilities of the IBM Flex System V7000, you must 
purchase a feature license for IBM Flex System V7000 Remote Mirroring Software. This 
license is based on the quantity of enclosures that are authorized for the feature. 
To determine the number of authorized enclosures needed you should count all enclosures 
on the system that are managed by the IBM Flex System V7000 Disk System, including each 
internal enclosure licensed with the IBM Flex System V7000 Base Software  and each 
external enclosure licensed with the IBM Flex System V7000 External Virtualization Software. 
This should be done at both the ends of the mirroring relationship. The location with the least 
number of members is the location that defines the number of licenses needed for each 
location site. 
For example, if you have site A with a DS5020 consisting of three enclosures managed by an 
IBM Flex System V7000 consisting of one control enclosure and one expansion enclosure 
mirroring to a partner at site B with an IBM Flex System V7000 consisting of one control 
enclosure and two expansion enclosures and no external virtual storage system attached, 
then in order to authorize remote mirroring for this configuration you will need a license to the 
IBM Flex System V7000 Remote Mirroring Software, for a quantity of six enclosures; three for 
site A and three for site B. If however, in the future you were to grow your site B system to 
include more enclosures or an external virtualized system you would then need to re-evaluate 
the licensing to add the appropriate number for the new configuration of the site with the 
fewest enclosures managed.
Remote mirroring Flex System V7000 with an SVC in the mix, because of a difference in 
metrics, SVC mirroring can be licensed for a subset of the total storage virtualized. However, 
the IBM Flex System V7000 and the IBM Storwize V7000 still must used the above model for 
their licensing.
2.6.4  Synchronous / Asynchronous Remote Copy
The general application of Remote Copy seeks to maintain two copies of data. Often, the two 
copies are separated by distance, but not always.
The Remote Copy can be maintained in one of two modes: synchronous or asynchronous.
With the IBM Flex System V7000 Storage Node, Metro Mirror and Global Mirror are the IBM 
branded terms for the functions that are synchronous Remote Copy and asynchronous 
Remote Copy.