Operating Systems

In the October/November 2009 issue, we discussed changes in SUSE Linux Enterprise Server (SLES) 11 to software packaging and software selections, z/VM interoperability, the installer, network configuration, and system management/ configuration. This article examines additional tools and functions.

Install and Maintenance Tool Architecture

Yet another Setup Tool (YaST) and the installer received an internal working over and facelift. The internal work reduced the amount of duplication of code and functions. Many users have told Novell that the old Partitioner was confusing to even experienced Linux users. The external facelift provided a more consistent user interface and a completely new Partitioner interface. For people accustomed to the old Partitioner, it will take awhile to regain familiarity, but new users seem to think it’s much simpler and easier to use.

The update stack shipped with SLES10 was completely reworked. It was slow, CPU- and I/O-intensive, and refreshed itself far too often. Mainframe users were better off disabling ZENworks Management Daemon (ZMD) until they were ready to actually install maintenance. Further, YaST and ZMD didn’t always agree on what was installed or available for update, since they each kept their own set of information. These concerns seem to have been addressed in SLES11. The command line interface that replaces the rug command is “zypper.” There’s no daemon running in the background, consuming resources and waking up idle z/VM guests. The significant changes are that YaST and zypper get their information from the same place, and zypper is much easier on CPU.

Here’s another major heads-up for enterprise customers: As shipped, SLES11 is officially supported only on z9 and z10 hardware. It will run on any zSeries and System z box, but won’t be considered a supported configuration for production use unless on a z9, z10, or future-generation system.

File Systems

EXT3 is now the default file system during installation or when adding new file systems. Reiserfs and XFS are still included and will be fully supported for the life of SLES11.

Oracle Cluster File System Version 2 (OCFS2) is now a Portable Operating System Interface for a UNIX (POSIX)- compliant file system. That means it can be used as a general purpose file system, and not just for Oracle applications. Using it for anything other than some kind of clustering, whether involving Oracle or not, would be fairly pointless, but possible. Clustered Logical Volume Manager 2 (C-LVM2) replaces Enterprise Volume Management System (EVMS) (alas, EVMS!), which is no longer included. This file system, and OCFS2 and C-LVM2 enablement in openAIS/Pacemaker, has been moved into SUSE Linux Enterprise High Availability Extension (SLE HA) 11 and is no longer part of the SLES11 base.

Dynamic enlargement of a Fibre Channel Logical Unit Number (LUN) is now supported, as is online enlargement of a multi-pathed device. This can save you from having to move a lot of data if it turns out the LUNs were sized too small.

As noted in the October/November article, there also are several technology previews in this release related to filesystems, EXT4, eCryptfs, and read-only root filesystems. The read-only root filesystem is especially interesting with the recent release of the IBM Redpaper documenting the use of the technique in rapidly producing cloned systems.

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