IBM Z10 EC manual Availability Functions, Hardware System Area HSA, Enhanced Book Availability

Availability Functions

With the z10 EC, signifi cant steps have been taken in the area of server availability with a focus on reducing pre- planning requirements. Pre-planning requirements are min- imized by delivering and reserving 16 GB for HSA so the maximum confi guration capabilities can be exploited. And with the introduction of the ability to seamlessly include such events as creation of LPARs, inclusion of logical subsystems, changing logical processor defi nitions in an LPAR, and the introduction of cryptography into an LPAR. Features that carry forward from previous generation pro- cessors include the ability to dynamically enable I/O, and the dynamic swapping of processor types.

Hardware System Area (HSA)

Fixed HSA of 16 GB is provided as standard with the z10 EC. The HSA has been designed to eliminate planning for HSA. Preplanning for HSA expansion for confi gurations will be eliminated as HCD/IOCP will, via the IOCDS process, always reserve:

•4 Logical Channel Subsystems (LCSS), pre-defi ned

•60 Logical Partitions (LPARs), pre-defi ned

•Subchannel set 0 with 63.75k devices

•Subchannel set 1 with 64K-1 devices

•Dynamic I/O Reconfi guration – always enabled by default

•Concurrent Patch - always enabled by default

•Add/Change the number of logical CP, IFL, ICF, zAAP, zIIP, processors per partition and add SAPs to the con- fi guration

•Dynamic LPAR PU assignment optimization CPs, ICFs, IFLs, zAAPs, zIIPs, SAPs

•Dynamically Add/Remove Crypto (no LPAR deactivation required)

Enhanced Book Availability

With proper planning, z10 EC is designed to allow a single book, in a multi-book server, to be non-disrup- tively removed from the server and re-installed during an upgrade or repair action. To minimize the effect on current workloads and applications, you should ensure that you have suffi cient inactive physical resources on the remain- ing books to complete a book removal.

For customers confi guring for maximum availability we rec- ommend to purchasing models with one additional book. To ensure you have the appropriate level of memory, you may want to consider the selection of the Flexible Memory Option features to provide additional resources when completing an Enhanced Book Availability action or when considering plan ahead options for the future. Enhanced Book Availability may also provide benefi ts should you choose not to confi gure for maximum availability. In these cases, you should have suffi cient inactive resources on the remaining books to contain critical workloads while completing a book replacement. Contact your IBM rep- resentative to help you determine and plan the proper confi guration to support your workloads when using non- disruptive book maintenance.

Enhanced Book Availability is an extension of the support for Concurrent Book Add (CBA) delivered on z990. CBA makes it possible to concurrently upgrade a server by integrating a second, third, or fourth book into the server without necessarily affecting application processing. The following scenarios prior to the availability of EBA would require a disruptive customer outage. With EBA these upgrade and repair procedures can be performed concur- rently without interfering with customer operations.

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