System information

2 Sharing and maintaining SLES 10 SP2 Linux under z/VM
1.1 History
This paper was originally published as the IBM Redpaper Sharing and maintaining Linux
under z/VM, largely based on input from architects and system administrators from
Nationwide Insurance, published in February of 2008, available on the Web at:
http://www.redbooks.ibm.com/abstracts/redp4322.html
In 2009, it was updated, with most input coming from system administrators at Penn State
University.
This paper is available on the Web page:
http://linuxvm.org/present
Specifically, the paper is at the URL:
http://linuxvm.org/present/misc/ro-root-S10.pdf
The tar file associated with the paper is available at:
http://linuxvm.org/present/misc/ro-root-S10.tgz
Changes in this paper
The changes made in this version of the paper are as follows:
򐂰 It is based on z/VM 5.4 (previously 5.3).
򐂰 Linux is based on Novell/SuSE SLES 10 SP2 (previously SLES 10).
򐂰 Linux scripts and z/VM REXX EXECs have been updated or added.
򐂰 The Linux script to create a read-only system is now named mnt2rogld.sh (formerly
mkror.sh) to better follow the naming convention.
򐂰 Disk space of each Linux system increased: previously a read-write system occupied
3338 cylinders, or a single 3390-3. In this paper, a read-write system occupies 5008
cylinders, or half of a 3390-9. A read-only system has been increased to 1669 cylinders, or
half of a 3390-3.
򐂰 The directory /var/lib/rpm/ is bind-mounted read-only over the read-write /var/ file
system. This allows the RPM database on the golden image to be used and kept
synchronized with the read-only clones.
򐂰 A more detailed section on maintaining Linux, 1.7.2, “A more detailed maintenance
methodology” on page 53, was added.
1.2 Overview
Large operating systems, such as z/OS®, have, for several decades, leveraged shared file
structures. The benefits are reduced disk space, simplified maintenance and simplified
systems management. This paper describes how to create a Linux® solution with shared file
systems on IBM® System z™ hardware (the mainframe) running under z/VM®. It also
describes a maintenance system where the same Linux image exists on a test, maintenance
and gold virtual servers.
The benefits of such a system are the following:
򐂰 Extremely efficient resource sharing: which maximizes the business value of running
Linux on System z