Справочник Пользователя для IBM Flex System V7000 Expansion Enclosure 4939H29

Draft Document for Review January 29, 2013 12:52 pm

IBM Flex System V7000 Storage Node Introduction and Implementation Guide

FlashCopy Consistency Groups are used to group multiple copy operations together that 
have a need to be controlled at the same time. In this way the group can be controlled by 
starting, stopping, and so on, with a single operation. Additionally, the function will ensure that 
when stopped for any reason, the IOs to all group members have all stopped at the same 
“point-in-time” in terms of the host writes to the primary volumes, ensuring time consistency 
across volumes.

Clicking FlashCopy



 Consistency Group opens the window shown in Figure 5-56. This 

window enables FlashCopy relationships to be placed into a consistency group. You can also 
use start and stop commands against the FlashCopy consistency group from this window by 
right-clicking the relationship.

Consistency groups address the problem of applications having related data that spans 
multiple volumes. In this situation, FlashCopy operations must be performed in a way that 
preserves data integrity across the multiple volumes. One requirement for preserving the 
integrity of data being written is to ensure that dependent writes are run in the intended 
sequence of the application.