IBM z/OS guide

On a z990, the scope of Channel Subsystem I/O Priority Queuing is a Logical Channel SubSystem.

Channel Subsystem Priority Queuing complements the IBM Enterprise Storage Server capability to manage I/O priority across CECs.

With IRD, the combination of z/OS and zSeries working in synergy extends the world-class workload management tradition of S/390 and OS/390 to ensure that the most important work on a server meets its goals, to increase the efﬁ ciency of existing hardware, and to reduce the amount of intervention in a constantly changing environment.

Parallel Sysplex Professional Services

IBM provides extensive services to assist customers with migrating their environments and applications to beneﬁ t from Parallel Sysplex clustering. A basic set of IBM services is designed to help address planning and early implementation requirements. These services can help you reduce the time and costs of planning a Parallel Sysplex environment and moving it into production. An advanced optional package of services is also available and includes data sharing application enablement, project management and business consultation through advanced capacity planning and application stress testing. For more information on Parallel Sysplex Professional Services, visit IBM’s Web site at ibm.com/servers/eserver/zseries/pso/ services.html.

Geographically Dispersed Parallel Sysplex

The GDPS solution, based on Peer-to-Peer Remote Copy (PPRC), referred to as GDPS/PPRC, is designed with the attributes of a continuously availability solution. PPRC is a

hardware solution that is designed to synchronously mirror data residing on a set of disk volumes, called the primary volumes in site 1, to secondary disk volumes on a second system in site 2. Only when the primary storage subsystem receives “write complete” from the secondary storage sub- system is the application I/O signaled completed. GDPS/ PPRC complements a multisite Parallel Sysplex environ- ment by providing a single, automated solution to dynami- cally manage disk and tape storage subsystem mirroring, processors, and network resources to allow a business

to attain “continuous availability” and near transparent business continuity/disaster recovery without data loss. GDPS/PPRC provides the ability to perform a controlled site switch for both planned and unplanned site outages, while maintaining full data integrity across multiple storage subsystems. GDPS/PPRC is designed to be application independent and therefore is expected to be able to cover the customer’s complete application environment. GDPS supports both the synchronous Peer-to-Peer Remote Copy (PPRC) as well as the asynchronous Extended Remote Copy (XRC) forms of remote copy. GDPS/PPRC is a con- tinuous availability solution and near transparent business continuity/disaster recovery solution that is designed to allow a customer to meet a Recovery Time Objective (RTO) of less than an hour, a Recovery Point Objective (RPO) of no data loss, and protects against metropolitan area disasters (up to 40 km between sites). GDPS/XRC is a business continuity/disaster recovery solution that allows a customer to meet a RTO of one to two hours, an RPO of less than a minute, and helps protect against metropolitan as well as regional disasters, since the distance between sites is unlimited. XRC can use either common communi- cation links and channel extender technology or dark ﬁ ber as the connectivity between sites.