IBM DS8000 manual IBM TotalStorage FlashCopy, IBM TotalStorage Metro Mirror Synchronous Pprc

IBM TotalStorage FlashCopy

FlashCopy can help reduce or eliminate planned outages for critical applications. FlashCopy is designed to provide the same point-in-time copy capability for logical volumes on the DS6000 series and the DS8000 series as FlashCopy V2 does for ESS, and allows access to the source data and the copy almost immediately.

FlashCopy supports many advanced capabilities, including:

￿Data Set FlashCopy

Data Set FlashCopy allows a FlashCopy of a data set in a zSeries environment.

￿Multiple Relationship FlashCopy

Multiple Relationship FlashCopy allows a source volume to have multiple targets simultaneously.

￿Incremental FlashCopy

Incremental FlashCopy provides the capability to update a FlashCopy target without having to recopy the entire volume.

￿FlashCopy to a Remote Mirror primary

FlashCopy to a Remote Mirror primary gives you the possibility to use a FlashCopy target volume also as a remote mirror primary volume. This process allows you to create a point-in-time copy and then make a copy of that data at a remote site.

￿Consistency Group commands

Consistency Group commands allow DS8000 series systems to hold off I/O activity to a LUN or volume until the FlashCopy Consistency Group command is issued. Consistency groups can be used to help create a consistent point-in-time copy across multiple LUNs or volumes, and even across multiple DS8000s.

￿Inband Commands over Remote Mirror link

In a remote mirror environment, commands to manage FlashCopy at the remote site can be issued from the local or intermediate site and transmitted over the remote mirror Fibre Channel links. This eliminates the need for a network connection to the remote site solely for the management of FlashCopy.

IBM TotalStorage Metro Mirror (Synchronous PPRC)

Metro Mirror is a remote data mirroring technique for all supported servers, including z/OS and open systems. It is designed to constantly maintain an up-to-date copy of the local application data at a remote site which is within the metropolitan area (typically up to 300 km away using DWDM). With synchronous mirroring techniques, data currency is maintained between sites, though the distance can have some impact on performance. Metro Mirror is used primarily as part of a business continuance solution for protecting data against disk storage system loss or complete site failure.

IBM TotalStorage Global Copy (PPRC Extended Distance, PPRC-XD)

Global Copy is an asynchronous remote copy function for z/OS and open systems for longer distances than are possible with Metro Mirror. With Global Copy, write operations complete on the primary storage system before they are received by the secondary storage system. This capability is designed to prevent the primary system’s performance from being affected by wait time from writes on the secondary system. Therefore, the primary and secondary copies can be separated by any distance. This function is appropriate for remote data migration, off-site backups and transmission of inactive database logs at virtually unlimited distances.

Chapter 1. Introduction to the DS8000 series 9