Operating Systems

While working on my next column, the prospect of reviewing the SLES 11 release developed into a significantly larger project than I had anticipated. Therefore, instead of my usual “Linux on System z” column in this issue, I present you with this article, which details the many features of SUSE Linux Enterprise Server 11 (SLES 11).

Novell launched SLES 11 on March 24, 2009. As is typical of such version updates, close cooperation with IBM and others resulted in numerous specific enhancements for IBM hardware and software. IBM requested approximately 100 features specific to System z. This article examines many of those changes as well as features of general interest on all hardware platforms.

Software Packaging

One of the more frequent complaints about SUSE Linux Enterprise is the large number and size of packages required because of inter-package dependencies or Novell’s choice of compile options. For SLES 11 a number of individual packages were broken into several packages, as is commonly done with other distributions such as Debian and Fedora. The intent was to provide core functionality in one package, which would require few or no other packages. Other packages might provide extra functions—a graphical interface, for example—which would then require a large number of other packages to be installed. This approach enables system administrators to have more control over how “bloated” their systems become.

A second approach taken was to create an extremely minimal system pattern, mainly intended for appliances. This configuration pattern installs roughly 260 packages, taking up less than 600MB of disk space. It Initial Program Loads (IPLs) with very little additional function; however, it forms a much more attractive basis for creating a stripped-down standard image.

In SLES 11, the kernel has been split into multiple Red Hat Package Manager (RPM) packages:

Kernel-default-base contains the actual kernel and a small number of modules for things such as Small Computer System Interface (SCSI) and the EXT3 file system.

Kernel-default includes all the other kernel modules and particularly the hardware-dependent ones.

Kernel-default-man contains actual man pages explaining the various messages emitted from the System z-specific kernel modules. This message catalog could be considered a very rough beginning of a Linux for System z messages and codes manual.

One significant change that enterprise customers should be aware of is that the packages relating to High Availability (HA) clustering and Mono have been split into separate “extensions.” System z subscribers will automatically have access to these extensions. Subscribers from other platforms, however, will have to pay extra for them, unless they meet the conditions to be “grandfathered” in at no additional cost. A future article will cover this in more detail.

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