Линейка мэйнфреймов IBM System z9

Line of mainframe computers

IBM System z9 is a line of IBM mainframe computers. The first models were available on September 16, 2005. The System z9 also marks the end of the previously used eServer zSeries naming convention. It was also the last mainframe computer that NASA ever used.

System z9 is a mainframe using the z/Architecture, previously known as ESAME. z/Architecture is a 64 bit architecture which replaces the previous 31 bit addressing/32 bit data ESA/390 architecture while remaining completely compatible with it as well as the older 24 bit addressing/32 bit data System/360 architecture. The primary advantage of this arrangement is that memory intensive applications like DB2 are no longer bounded by 31 bit memory restrictions while older applications can run without modifications.

With the announcement of the System z9 Business Class server, IBM has renamed the System z9 109 as the System z9 Enterprise Class server. IBM documentation abbreviates them as the z9 BC and z9 EC, respectively.

There are several functional enhancements in the System z9 compared to its zSeries predecessors. Some of the differences include:

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 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, 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 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.

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.

The System z9 supports up to 60 LPARs, up from the previous maximum of 30.

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.

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.

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.

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.)

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.

The acquisition price for the System z9 ranges from "about $100,000" (IBM reported U. S. 2006 price, 2096 A01 model) to millions of dollars for the 2094 S54. (These prices are for new installations. Generally there are lower prices when upgrading from the immediate predecessor model, more like many software products and quite unlike most other hardware products.) For comparison, when new, the zSeries z890 had a starting price about twice that of the System z9 BC.

In February 2008, the IBM System z10 Enterprise Class was announced (and later in 2008 the z10 Business Class (BC) was announced). The z10 features quad core technology, for up to 64 processors. The z10 has a number of power saving, space saving and throughput improvements compared to the z9.