There are several functional enhancements in the System z9 compared to its zSeries predecessors. Some of the differences include:
Support Element & HMC The
Support Element is the most direct and lowest level way to access a mainframe. It circumvents even the
Hardware Management Console and the
operating system running on the mainframe. The HMC is a
PC connected to the mainframe and emulates the Support Element. All preceding zSeries mainframes used a modified version of
OS/2 with custom software to provide the interface. System z9's HMC no longer uses OS/2, but instead uses a modified version of
Linux with an OS/2 lookalike interface to ease transition as well as a new interface. Unlike the previous HMC application on OS/2, the new HMC is web-based which means that even local access is done via a
web browser. Remote HMC access is available, although only over an
SSL encrypted
HTTP connection. The web-based nature means that there is no longer a difference between local console access and remote access, which means a remote user potentially has full control if authorized, allowing more flexibility for locating systems within data centers. IBM refers to the new HMC as a "closed platform" which does not allow the user to install software or access the
command line interface to increase security and stability. The HMC is also firewalled by default with a minimal number of open ports for remote access.
Program Directed Re-IPL Program Directed Re-IPL is a new feature for
Linux on System z9. It allows Linux systems running in an
LPAR to re-
IPL (reboot) themselves without operator intervention. This is accomplished by the System z9 storing the device and load parameters used to initially IPL the system.
DB2 and VSAM features DB2,
VSAM, and other data storage formats achieve greater I/O performance thanks to a new System z9 feature called a
MIDAW. Also, the System z9 introduces the , a new type of processor that accelerates certain specific DB2 tasks. Modified Indirect Data Address Words (MIDAWs) are a
channel programming capability of the
IBM System z9 processor range, and all subsequent ranges. The MIDAW facility is an extension to the pre-existing Indirect Data Address Word (IDAW) channel programming capability, providing support for more efficient
FICON channel programs. MIDAWs allow ECKD channel programs to read and write to many storage locations using one channel command, which means fewer signals up and down the channel are required to transfer the same amount of data. This reduction is particularly noticeable for Extended Format
data sets, accessed through Media Manager. Examples include Extended Format Sequential data sets, Extended Format
VSAM data sets and certain types of
DB2 tablespaces. While each of these data set organizations have alternatives, each has a distinct set of advantages, whether in the area of performance, space saving (through hardware-assisted
data compression), or scalability (by allowing an individual data set to exceed 4 GiB).
Java features Java 1.4 and higher support both
32-bit and
64-bit operation on z9. The System z9 also supports the
zAAP processor, which allows most of the Java workload to be offloaded from the normal instruction processors. Java workloads executed by the zAAP processor do not count towards the
IBM-rated capacity of the z9. This reduces the z9's total cost of ownership compared with other IBM platforms, as otherwise IBM would raise a customer's (software) license fees after installing an additional (hardware) processor. The zAAP also enables integration of new Java based Web applications with core z/OS backend database environment for high performance, reliability, availability, and security.
Cryptography The System z9 adds 128-Bit
Advanced Encryption Standard (AES) to the list of hardware-based cryptographic algorithms. Other hardware-boosted features include additional random number generation and
SHA algorithms. This specialized encryption hardware means System z9 potentially outperforms other platforms which must rely on encryption software.
LPARs The System z9 supports up to 60
LPARs, up from the previous maximum of 30.
Larger memory capacity The System z9 supports twice its immediate predecessors' maximum memory configurations: now up to 512 GB for the z9 EC and up to 64 GB for the z9 BC.
Concurrent system board replacement The System z9 supports nondisruptive processor and memory replacement. That means a technician can replace an entire system board without ending any applications and without restarting any operating systems. In most configurations a System z9 can even manage this feat without any reduction in performance or capacity for the running applications.
4 Gbit FICON and FCP In May 2006, IBM added 4 Gigabit
FICON and
FCP support to the System z9 for faster I/O to storage devices. IBM also added a lower cost 2-port 4 Gbit FICON/FCP I/O adapter to the System z9 option list.
Smooth subcapacity increments Also in May 2006, IBM introduced subcapacity settings to its high end model. For the first time mainframe processors now allow small, smooth steps through the entire processor range. This feature allows IBM's customers to control their software costs precisely and to pay for only exactly as much capacity as they need without harsh price discontinuities at certain capacity increments. (IBM started offering variable subcapacity software pricing in 2000, and some other software vendors now offer similar terms, so hardware subcapacity settings are of primary interest when running so-called full capacity software products.)
Group capacity limits Available with
z/OS Release 8, Group Capacity Limits allows an installation to define a group of LPARs within a single z9 or z10 machine whose capacity usage can be limited to a specific number of MSUs. Usage is based on the rolling 4 hour average CPU consumption, also in MSUs. A group need not necessarily be the same as an LPAR Cluster. LPARs can participate whether they are in a
sysplex or not.
Separate processor pools While previous mainframe generations (including the predecessor
zSeries z990) supported specialty processors, such as zAAPs and ICFs, these were all managed by PR/SM out of the same processor pool (Pool 2). The IBM System z9 EC introduced the concept of separate pools for different types of specialty processor. This greatly eases the tasking of managing and measuring the performance of the different processor types. With z9 (and
IBM System z10) the following pools are defined: • 1 General-purpose processors • 3 IFLs • 4 zAAPs • 5 ICFs • 6 Pool 2 is no longer used. In addition to these 5 pools of
characterized processors, there are three other categories of processor: • Service Assist Processors (for assisting with I/O operations) which all machines have. • Spare processors (to replace characterized processors in the event of a failure) which all machines have. • Unpurchased processors (which can be purchased and then characterized) which all but the most fully characterized machines have. == Models ==