Red Hat Linux 5.0
The biggest change in 5.0 is the switch to a different C library, Glibc. Linux 2.1.x kernel development is hopefully nearing the end of a long and exceptionally chaotic development cycle—the new dcache, finer grained SMP and a raft of new features and performance enhancements are causing trouble. This is nothing new for Linux, but it's been a long time since the last “stable” release of 2.1. On top of all the ongoing kernel changes is a new standard GNU C library, Glibc. Glibc has a clean threads implementation, transparent support for IPv4 and IPv6, improved linking and other incremental improvements that ultimately turn it into a whole new animal. The combination of new library plus new kernel code makes it harder to isolate bugs.
By biting the bullet now, choosing to bundle the new C library and stick with a proven release of the kernel, Red Hat is doing the world's Linux developers and ultimately its users a service. Threading is a standard feature of competing operating systems, such as NT and Solaris, and very important to Linux's new bleeding edge GUIs: KDE and Enlightenment. In the short term there will be a flurry of Red Hat 5.0 incompatible software which should be cleaned up by the time you read this article.
The graphical on-line help system is still hopelessly crude. The tools (notably htdig) exist to make an excellent searchable archive of all the included html/text documentation, and it's too bad that the default help system is so slow and clunky. The Red Hat 5.0 network configurator now has support for configuring a PAP (password authentication protocol) PPP session, which saves some troublesome scripting.
Red Hat 5.0 includes many security enhancements. Because of the change to Glibc, all of the applications had to be recompiled and relinked. As a result, it is hard to tell which programs have been upgraded or changed.
Yet, there are (as of this writing) 54 additional patches in http://www.redhat.com/support/docs/rhl/rh50-errata-general.html and 8 in Intel, including a critical kernel upgrade that blocks the Teardrop attack. The Teardrop Denial of Service attack immediately made the kernel (2.0.30) shipped with this release obsolete. Someone decided to hit me with Teardrop, crashing my servers every night for two weeks. The newest kernel (2.0.32) successfully detects, logs and blocks this attack.
You should immediately install a new kernel and many of the RPMs if you intend to use your 5.0 system on the Internet. On installing a new release, the first commands I run are:
mkdir /usr/local/rpms cd /usr/local/rpms ncftp -R -d 5 \ ftp.redhat.com:/pub/linux/redhat-5.0/ rpm -i -upgrade *
Substitute your favorite mirror for the FTP address. The wget utility (available from the GNU archives) is slightly better for mirroring sites in this fashion, as it supports both FTP and HTTP, partial file/directory transfers, time-stamped updates and automatically uses PASV mode (necessary for FTP to work through a firewall).
The fact that patches for these problems are so readily available is a tribute to the flexibility of RPM and the hard working bunch of Linux folk who are countering the persistent cracking community.
RPM's FTP and FTP proxy support are now documented on the man page, but to use RPM effectively to distribute your own software requires the book, Maximum RPMs, available from Red Hat.
The UNIX world needs a software installer of the caliber of the Windows 95/NT Installshield. RPM is a good, even great start, but Debian Linux's installer beats the RPM/GLINT combination for both interactivity and ease of use. An RPM/GLINT release combining the best features of RPM and Debian would be a good thing.
The RedBaron web browser has been dropped—Netscape 4.04 is freely available and is a vastly superior product. You will have to download it from the Net, however, as it's not bundled on the CD—yet.
Metro-X boasts of a nice configuration screen, added card support and improved color depth, resolution and performance over the XFree86 release of the X server. In my case, Metro-X is of marginal utility—the XFree and S.u.S.E. drivers for my ET6000 and Mystique cards are as fast or faster and more reliable. You have to configure XFree in order to even try to configure Metro Link in many cases.
Metro Link has some excellent add-on libraries, notably OpenGL, which is experiencing enormous interest in light of the PC gaming phenomenon. If you intend to use OpenGL, the bundled Metro-X server saves you money against the purchase of the extra OpenGL libraries. Your other choice is the freely available OpenGL clone, MESA, which converts OpenGL calls into X code—which is, in theory, much slower.
The new backup program with the unwieldy name of BRU 2000-PE is straightforward enough for a single-user environment. In my environment, where I have to back up multiple machines to a single tape drive, through a firewall, the combination of cpio/dump and ssh works exceptionally well.
The newly bundled RealAudio 5.0 server and client are very sexy products. I've now hooked up my studio to my main Linux box so that I can broadcast live sessions to the Internet. The server operated flawlessly. The live encoder worked great once I had a working sound card and worked out the correct encoding rate. The 95/NT versions of the software have nicer interfaces, but I've already had months and months of uptime on my primary RealAudio server.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
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- Non-Linux FOSS: Caffeine!
- Rogue Wave Software's Zend Server
- Doing for User Space What We Did for Kernel Space
- Parsing an RSS News Feed with a Bash Script
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide