134 IBM ^ zSeries 990 Technical Guide
6.1 Operating system support
There are many significant changes in the z990 architecture and hardware features when
compared to the z900 processor. Extensive software support has been made available to
existing OS levels via compatibility and Exploitation Support to accommodate these changes
in the OS/390, z/OS, z/VSE, VSE/ESA, TPF, z/VM and Linux on zSeries operating systems.
Table 6-1 summarizes supported software on the z990.
Table 6-1 z990 software support summary
6.2 z/OS software support
z/OS software support has been designed at two levels: Compatibility Support and
Exploitation Support.
6.2.1 Compatibility Support for z/OS
Compatibility Support for z/OS software is delivered in several ways, depending on the
version of release of z/OS.
Operating system ESA/390
Compatibility Exploitation
OS/390® Version 2 Release 10 Yes Yes Yes No
z/OS Version 1 Release 2 No
a. 31-bit mode is only available as part of the z/OS Bimodal Migration Accommodation software
program. The program is intended to provide fallback support to 31-bit mode in the event that
it is required during migration to z/OS in z/Architecture mode (64-bit).
Ye s Ye s N o
z/OS Version 1 Release 3 No
Ye s Ye s N o
z/OS Version 1 Release 4 No
Ye s Ye s Ye s
z/OS Version 1 Release 5 and 6
b. z/OS 1.6 is planned to be available in September 2004.
No Yes Included Included
Linux for S/390 Yes No Yes Yes
Linux® on zSeries No Yes Yes Yes
z/VM Version 3 Release 1 Yes Yes Yes No
z/VM™ Version 4 Release 3 Yes Yes Yes No
z/VM Version 4 Release 4 Yes Yes Included Included
z/VM Version 5 Release 1 No Yes Included Included
VSE/ESA™ Version 2
Release 6 and 7
Ye s N o Ye s Ye s
z/VSE Version 3 Release 1
c. The z/VSE operating system can execute in 31-bit mode only. It does not implement z/Archi-
tecture, and specifically does not implement 64-bit mode capabilities. The z/VSE operating sys-
tem is designed to exploit select features of IBM
^ zSeries hardware.
Yes No Included Included
TPF Version 4 Release 1
(ESA mode only)
Ye s N o Ye s N o
Chapter 6. Software support 135
z990 compatibility for selected OS/390 and z/OS releases
OS/390 V2.10, z/OS V1.2, and z/OS V1.3 require the Web delivered Compatibility Support to
run on a z990.
Compatibility Support allows these releases to:
򐂰 Define a z990 environment with HCD
򐂰 Run on a z990 processor in a logical partition in LCSS-0, using an LPAR ID equal to or
less than x’F’
򐂰 Coexist in a sysplex that contains a z990 processor
򐂰 Coexist with z990 processors sharing disk devices outside of a sysplex
Compatibility Support requirements
Compatibility Support is required under the following circumstances:
򐂰 Compatibility Support is required for
all images running on a z990.
򐂰 Compatibility Support is required on
any image that is used for defining the I/O
configuration for the z990.
򐂰 Compatibility Support is required on
all images in a sysplex, whether running on a z990 or
not, if a Coupling Facility logical partition for that sysplex is running on a z990 and has an
LPAR identifier greater than 15 ( x’F’).
Compatibility Support allows the supported operating systems to run in LCSS 0 on the z990
processor. It is not possible to run z/OS or OS/390 in LCSSs 1, 2, and 3, even with the
compatibility maintenance. This is supported on z/OS 1.4 with the Exploitation Support and
subsequent releases.
Compatibility Support can run on any processor that is already supported by one of the listed
operating systems. For example, you can install Compatibility Support on a z/OS V1.2 system
that is running on an IBM 9672 G5 processor.
Figure 6-1 on page 136 shows a situation where the Compatibility Support is
not required for
systems not on the z990.
Attention: Compatibility and Exploitation Support is not available for z/OS 1.1
Note: A Coupling Facility logical partition can reside in any Logical Channel Subsystem.

Get IBM eServer zSeries 990 Technical Guide now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.