News in brief from IBM's Linux Technology Center

LTC bulletin: July 31, 2001

Maya Stodte (mstodte@us.ibm.com)
Contributing editor, developerWorks
July 2001

Our biweekly news in brief from the Linux Technology Center -- where all the Linux-related technologies happening inside IBM are tracked -- includes new project releases like System Configurator and patches to SNIA and CIMOM, as well as many new project versions, including Open AFS, JFS, DProbes, and Omni. To find out more about any of these projects, go directly to the Linux Technology Center.

Open AFS
The Open AFS Project has released version 1.1.1, which fixes a problem with symlinks and makes EOF exit the backup program. The previous release, 1.1.0 builds with autoconf, enables AFSDB support by default, fixes SMP support for RedHat Linux 7.1, according to the release notes.

AFS is a distributed enterprise file system with a data management model that was open sourced by IBM's Transarc lab last September. It offers a client-server architecture for file sharing in which files stored in AFS are accessed through user installations.

ACP Modem Driver
The ACP Modem (MWave) project has released version 1.0., which includes a few changes, as well as the latest code from the driver patch 2.4.6-20010718. Changes to this patch, as listed in the changelog, are:

Module now builds as mwave.o instead of mwavedd.o
Driver now registers it's UART with the serial driver
Some global function name cleanups.

The ACP modem (Mwave) for Linux is a WinModem. "It is composed of a loadable kernel module and a user-level application," the project site explains. "Together these components support direct attachment to public switched telephone networks (PSTNs) and support selected worldwide countries." It supports the IBM ThinkPad 600E and the standard communications port interface (ttySx), and is compatible with the Hayes AT Command Set.

DProbes
DProbes has released version 2.2.0. Among the substantial changes made in this release (as noted in the changelog) are:

Opcode verification can be bypassed by using the new command line option --dont-verify-opcodes, if the probe point location is specified by a symbol
The values specified in gv= and lv= in the rpn program are now ensured to be less than a compiled in maximum to ensure that an unreasonably high value does not cause any problems to kmalloc
dr_alloc now allocates global debug registers in the reverse order to avoid clashing with other debuggers (GDB) usage of debug registers as much as possible.

Richard Moore has been discussing development on Dprobes, and his other project, GKHI, in a number of white papers, which were covered in the LTC Bulletin from July 16.

DProbes is a debugging facility designed to work under extreme or inaccessible conditions. It gathers diagnostic information by dynamically firing probes into executing code modules, relying on user written probe-handlers (programs written in assembly-like code based on Reversed Polish Notation).

iSeries
The iSeries project has released updated patches for the 2.4.3 kernel, which include a scheduler fix for systems with small memory (like 64MB) with a SMP kernel, VIOCD and VIOTAPE cleanups, and pcnet32 performance improvements. The iSeries patches are consecutive, and must be applied in order.

The IBM e-server iSeries is a set of enterprise servers designed for e-business solutions. Although Linux distributions for the iSeries are yet to be made available, you can run Linux on the iSeries unsupported. Note that this requires the next version of OS/400, which is still in beta testing.

SNI CIMOM
The patches to SNIA and CIMOM have been updated. They include a delclass patch written by Douglas Shue, an instname patch and a repository patch by Viktor Mihajlovski, and a properties patch and an auth patch by Quan Wang, who, together with I-Ju Wang also wrote an, outparm val patch.

SNIA is the Storage Networking Industry Association. The CIMOM (Common Information Model Object Manager) technology from SNIA provides client and server with CIM/WBEM technologies. "CIM," in the words of Viktor Mihajlovski, "is an object-oriented data model for Systems Management (defined by the Distributed Management Task Force). Web Based Enterprise Management (WBEM) is a set of standards centered around CIM enabling systems to handle remote management. Resource specific plugins, called providers or instrumentation, are invoked by the CIMOM to access and modify information on the managed system."

Generalized Kernel Hooks Interface
GKHI has released version 1.2. The changelog notes the following updates in this release: rewritten to conform to kernel coding style, available as a kernel patch and can now be built into the kernel or as a module, and offers hooks on all architectures as well as optimizing framework for hooks on particular architectures. GKHI is now distributed as a patch against the Linux kernel. Current work focuses on A /proc interface to allow hook status to be viewed and hooks to be enabled and disabled by a user interface.

The GKHI generalized mechanism manages exits in kernel space; it is suitable for use in first failure data capture applications, security hooks, and optional serviceability tools. "A hook is a location in the kernel that calls out of the kernel to a kernel module routine - a hook exit routine," explains Richard Moore. "It enables many kernel enhancements, which are otherwise self-contained, to become loadable kernel modules and retain a substantial degree of independence from the kernel source. This affords advantages for maintenance and co-existence with other kernel enhancements."

Omni
The Omni project has released version 0.3.2. The new release fixed a broken patch file for the 5.50 release of Ghostscript. More substantial changes were made to the project in the 0.3.1 release, which were covered in the LTC Bulletin from July 16.

Omni edits old device description files in order to create new devices and allows for the subclassing of previous device features, which simplifies printer driver development.

System Configurator
The System Configurator project has released version 0.3.1. "We are currently using this base as the base for the first pass at SystemImager / System Configurator merging," notes the development team. "As of this release the Bootstrapping layer has been added, with support for Lilo, Grub, and Yaboot bootloaders. The build process was also made simpler through the inclusion of non-core Perl modules in our distribution."

System Configurator provides a consistent API for the configuration of Network Scripts, Hardware, and Bootstrapping after the software installation on a Linux machine. It is designed to work across all distributions and architectures. System Configurator, along with System Installer, is the LTC's contribution to the System Installation Suite, which emerged out of a collaboration between the former LUI project and VA Linux's System Imager. Read more about the merger in the LTC Bulletin from June 19.

iSCSI Initiator Project
iSCSI, another new project hosted on the LTC, is being made available to help foster the IETF iSCSI work group and their draft iSCSI standard. The Small Computer System Interface (SCSI) is a processor-independent standard for system-level interfacing. SCSI storage protocols over IP, commonly referred to as iSCSI, will enable the transport of SCSI I/O traffic over standard IP networks. Formal iSCI standards are expected to be finalized by the end of this year. IBM's storage networking includes Storage Area Networks (SAN), Network Attached Storage (NAS), and iSCSI, available through the IBM TotalStorage� IP Storage 200i, which provides storage directly attachable to an Ethernet LAN.

Linux Test Project
The Linux Test Project has been announced. The project, which is working on automated testing tools, will be hosted on SourceForge. The most recent release of the Linux Test Project, version 20010628, includes over 100 testcases. The project notes site the range of tests as covering:

Over 20 reliability network tests for remote procedure calls, network file systems, multicast, and various network commands
An assortment of robustness tests that cover pthreads, memory, filesystems, and disk I/O
Several tests for commands commonly used in an application development environment.

JFS
JFS has released drop thirty-nine, version 1.0.1. JFS released it's first beta (0.1.0) in December of last year, followed by beta 2 (version 0.2.0) in March and beta 3 (version 0.3.0) at the end of April. JFS 1.0.0 was released at the end of June.

Changes to the utilities in drop 38 fixed a small logredo problem. The JFS changelog by Steve Best notes changes to the utilities in drop 39 (1.0.1) as follows:

Updated jfsprogs.spec file make it work on more distros
Add force option to mkfs so the confirmation message isn't displayed
Fixed fsck to handle index table on the root directory
Correctly place the built utilities in /sbin vs. /usr/sbin when using the make install option.

Changes to JFS in drop 38 fixed some general log problems. Changes to JFS in drop 39 (1.0.1), as noted in the changelog, reads as follows:

Fixed hang during copying files on 2.2.x series
Fixed TxLock compile problem
Fixed to correctly update the number of blocks for directories (this was causing the FS to show fsck error after compiling mozilla).
Fixed to prevent old data from being written to disk from the page cache.

The JFS todo list for the near- and long-term includes a fix for 2.2.* SMP kernel hangs, getting defrag capabilities operational in the FS, and integrating with LVM and SnapFS Snapshot file system.

The Journaled File System technology from IBM, currently used in its enterprise servers, provides a log-based, byte-level file system designed for high-throughput server environments. Work is underway to complete the port to Linux.

Next Generation POSIX Threads
The NGPT project has achieved near full POSIX compliance with version 1.0.0, its first stable general release suitable for production use. "It contains a kernel patch that provides a full implementation of the CLONE_THREAD flag option of the clone() API," as described in the release notes. "A diff is provided. Recent changes should be easily applied to all versions of the 2.4 kernel. A second optional patch for the kernel provides additional information in the /proc filesystem, without which ps reports each "kernel" thread as a separate process, much like the current implementation. Actual user threads remain invisible to ps and the /proc filesystem."

Because this is a general release, new problems with NGPT 1.0.0 may still arise and a few kinks, listed in the release notes, are still being worked out. Install notes are available from the NGPT site and a complete list of changes from version 0.0.0 to present are available in the Changelog. Most notable among the changes are support for additional platforms such as PowerPC and IA64 and stabilizing the package on SMP -- a focus of the 0.9.6 release.

The Next Generation POSIX Threading project derives from the GNU Pth package. It aims to solve problems associated with the pthreads library on Linux.

New project links
Project links have been added to the site for:

International Components for C/C++
International Components for Unicode for Java
Standards Based Linux Instrumentation for Manageability (SBLIM)
The Linux port of the Dynamic Probe Class Library project (just released)

News from these projects will be covered in more detail in the next installment of the LTC Bulletin.

Miscellaneous news

The Distributed Lock Manager Project has posted a draft review of it's users guide by Kristin Thomas.
Linux kernel patch to enable multi-quad ia32 NUMA machines by Martin J. Bligh has been released. Performance enhancements will follow.
The Linux Scalability Effort has released the Netbench Performance Evaluation for Linux. Andrew Theurer of the LTC recently posted preliminary results from an investigation into Linux 2.4 SMP scalability, using Netbench as a workload with Samba.
IBM is sponsoring a Linux Arabization Workshop in Cairo September 2-4. Participation is open and is accepting submissions for papers to be presented. The workshop is being produced in cooperation with the Saudi Computer Society, the Information Technology Association of Jordan, King Abdulaziz City for Science and Technology and the Saudi Linux User Group.

Resources

Read the previous LTC bulletins on developerWorks:
- July 16, 2001
- June 19, 2001
- May 21, 2001
- May 7, 2001
- April 23, 2001
Visit the Linux Technology Center and take a look Behind the scenes at the LTC.
Browse the Linux Documentation Page.
Learn more about the projects and patches covered in this LTC bulletin:
- ACP Modem Driver project (developerWorks)
- Distributed Lock Manager Project (developerWorks)
- DProbes project (developerWorks)
- GKHI project (developerWorks)
- International Components for C/C++ (developerWorks)
- International Components for Unicode for Java (developerWorks)
- iSCSI project (developerWorks) (find out more about the Storage Networking Industry Association)
- iSeries project (developerWorks)
- JFS project (developerWorks)
- The Linux port of the Dynamic Probe Class Library project (developerWorks)
- Linux Scalability Effort (SourceForge)
- Linux Test Project (SourceForge)
- Next Generation POSIX Threads project (developerWorks)
- Omni project (developerWorks)
- Open AFS Project
- Standards Based Linux Instrumentation for Manageability (SBLIM) (developerWorks)
- SNI CIMOM patch (developerWorks)
- System Configurator, System Installer and System Installation Suite(SourceForge)
Take our free JFS fundamentals tutorial.
Check out more Linux resources and more Open source resources on developerWorks.
Go to the Linux Arabization Workshop in Cairo, co-sponsored by IBM.
Find out more about IBM's storage networking and the IBM e-server iSeries.
Check outSNIA, the Storage Networking Industry Association and the Distributed Management Task Force.

About the author
Maya Stodte is a contributing writer and editor for developerWorks. She can be reached at mstodte@us.ibm.com.