I had an interesting phone conversation about a month ago. It went something like this (abbreviated for space): “Hey David, I have problem with a client's mail server [Caldera eServer 2.3]. It's been running great since I installed it two years ago, but a power failure caused it to shut down. Now, the system comes up, but the Ethernet interfaces won't come up.” Me: “Well, let's bring them up manually and see why they don't come up at bootup. Any problems with fsck?” Friend: “None. I've tried running ifconfig, but it won't configure the interfaces.” Me: “Run lsmod, if the drivers aren't installed. Let's do that first, then humor me and run ifconfig exactly as I give it to you.” Friend: “Modules are installed; ifconfig segfaults.” Me: “Segfaults? (With alarm bells going off in my head.) Let's replace the ifconfig RPM in case it was damaged when the system crashed (as I'm thinking, ifconfig is one of the least likely apps to go south). You'll have to use --force to replace the ifconfig package.” Friend: “It appears ifconfig can't be replaced, even with --force.” Me: “Please run lsattr ifconfig and tell me what you see.” Friend: “I see an 'i' to the left of the name.” Me (with Star Trek's “whoop, Intruder Alert” playing in my mind): “Humor me again. Run locate ifconfig.” Friend: “/sbin/ifconfig; /dev/sdg/.azgub/backup/ifconfig, /usr/man/man8/ifconfig.8.gz.” Me: “Well, you just found a rootkit hidden in /dev. Your client has been broken into. By the way, have any of the security patches been applied to that server since installation?” (No answer, but I assume not.)
It's a month since I sent a quote to fix his security problems and install a firewall (among other services). The intruder is still in this system, the Ethernet cards are in promiscuous mode, and the client seems oblivious to the dangers (says he's changed his passwords, so he's taken precautions—right). Who's inside? Why? Has this system with a fairly large pipe been used to break into other systems and/or act as a zombie to perform DDOS attacks? Some folks should not be allowed to remain connected to the Internet. Is he alone? Not hardly. My servers are pounded daily, my bandwidth being eaten by virii, automated attacks, etc. And, I'm paying for unnecessary bandwidth because of it. There should be a law.
Need to find out if you (or someone on your network) are contributing to the spam problem? This tool is all you need to help stop the spam problems on your network. Requires: libpthread, glibc.
This is an excellent start on a nice GTK agenda. It holds names, phone numbers and e-mail addresses in a PostgreSQL database. Currently available only in Spanish, changing the labels, etc., to English, German, whatever, should be fairly simple—although Internationalization would be the way to go. You can send e-mails from within this application, but you'll need an SMTP dæmon running. Should be an easily extended application for your database needs. Requires: libgtk, libgdk, libgmodule, libglib, libdl, libXext, libX11, libm, libpq, libssl, libcrypto, libcrypt, libresolv, libnsl, glibc.
If you need to find out more than you can get from /proc/cpuinfo, this may be what you need. It reads directly from the CPU registers, so it can provide more information than what most of us will need or even understand. Requires: glibc.
If you're looking for a way to give courses and tests over the Internet, ILIAS is another tool that will allow you to do this. Data on students, test scores, etc., are all maintained in a MySQL database. Requires: Apache w/PHP and MySQL, MySQL server, GD, zlib, freetype, libjpeg, ImageMagick, zip, unzip.
There are a lot of utilities out there for watching packets on your network, but this one is slightly different. It looks at the percentage of bandwidth use for packets. This little jewel can tell you very quickly that one of your abusers running Kazaa is gobbling 99.7% of the available bandwidth. Requires: libm, glibc.
This web application is probably one of the easiest ways to maintain your BIND zone files, even easier than Webmin's BIND module. Requirements are small, but it does mean running a web server on your DNS platform. I'll be watching this one as it develops, as the author has a number of interesting items on his to-do list. Requires: web server (Apache) capable of running CGI scripts, Perl, BIND 8 or 9.
This month's pick from three years ago wavered between two great programs: ntop and stickerbook, a great program for children (mine love it, but ntop won). This is now a much improved version of ntop. It has developed from a simple ncurses utility to an advanced web client using HTTPS or HTTP for connections, with graphing in gdgraph (optional). ntop now bears little resemblance to its former self and is easier to use and read. If you need a top-like utility for your network, you need this. Requires: libmysqlclient, libcrypt, libm, libssl, libpthread, libresolv, libnsl, libdl, libgdbm, libz, glibc. Until next month.
David A. Bandel (email@example.com) is a Linux/UNIX consultant currently living in the Republic of Panama. He is coauthor of Que Special Edition: Using Caldera OpenLinux.
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.
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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