EFS Systems on a Linux Base: Getting Started

12 EFS Systems on a Linux Base: Getting Started

2.1 General planning

These topics are relevant to any platform used for FLEX-ES and you should understand the

following discussions.

2.1.1 Production or sandbox

By production, we mean a high-performance, highly stable system. By sandbox, we mean a

convenient, easier-to-install system. These two categories do not cover all situations, of

course, but they are convenient terms. In the sense used here,

production implies some

combination of serious business, important work, maximum performance, or a

highly-stressed system. For example, a basic sysplex using multiple S/390 instances in a

ThinkPad falls in the production category, even if used only for self-education, because it

represents a highly-stressed system.

Production systems, in the sense used here, require a little more installation effort than a

sandbox system. For example, a production system should include:

򐂰 Superior hardware, including RAID disks and ECC or similar memory

򐂰 The latest BIOS updates and RAID firmware updates

򐂰 The latest Linux drivers and utilities for managing RAID adapters

򐂰 The latest Logical Volume Manager (LVM) updates (if LVM is used)

򐂰 The use of raw disk interfaces instead of simple Linux files for emulated S/390 volumes

򐂰 Installation of appropriate Linux fixes and updates

򐂰 Careful tuning of FLEX-ES disk buffers

򐂰 Selection of Linux partitions and file systems to avoid “file system full” exposures

For various redbook projects, we installed FLEX-ES systems using none of the above options

and other systems using most of these options. Both approaches produced useful, working

FLEX-ES systems. New users may start with a simple sandbox installation to gain experience

and confidence with FLEX-ES, while investing less time and effort than needed for a

production system. There is no firm dividing line between production and sandbox systems.

Your system may use some of the listed options and ignore others.

This redbook concentrates mostly on a sandbox installation, although “production-level”

facilities are briefly mentioned in various sections.

2.1.2 Selecting a Linux distribution

FLEX-ES is tested and supported only with selected releases of Red Hat Linux. It may work

with other Linux distributions, but there is no support if something goes wrong.

It is important to understand what is meant by a release of a Linux distribution:

򐂰 A Red Hat release contains a

stock Linux kernel; that is, a pre-built kernel that is installed

as part of the standard installation process. (There may be more than one stock kernel;

perhaps one for uniprocessors and another for SMPs.)

򐂰 There is a

kernel source tree that can be used to rebuild the kernel with different options.

򐂰 There are many

packages that can be selected during installation. For example, you may

want the gcc compiler, a Web server, X Windows interfaces, and so forth. Each of these

packages has its own release level.

For example, Red Hat 9.0 provides a stock kernel at level 2.4.20 (with a corresponding kernel

source tree) and the gcc compiler at level 3.2.2. For reasons discussed later, you may replace

the kernel source tree with a different level and build a new kernel at the different level. Your