Best of Technical Support
I successfully installed Red Hat v5.1 with X as the GUI. I have O'Reilly's book Learning Linux, which is a good reference. The only problem I have is that I cannot access /dev/fd0. When I type this command in an xterm, a message states that access to the device is forbidden. What am I supposed to do? I have looked up information on the Linux USENET listing, but I cannot find anything specific. —P. Kincaid, email@example.com
You either need to be root to access /dev/fd0 or belong to a group (e.g., floppy) to which users with access permissions to /dev/fd0 belong. On my system, it looks like this:
brw-rw-r-- 1 root floppy 2, 0 mai 5 1998 /dev/fd0
—Marc Merlin, firstname.lastname@example.org
The simplest way is to run the following command as root:
chmod 666 /dev/fd0
Bear in mind that this has security implications, especially on a multiuser system. —Scott Maxwell, email@example.com
When I want to start the X Window System, the system shows error messages—the first few lines look like this:
Could not find config file! -Tried: /root/XF86Config /etc/XF86Config /usr/X11R6/lib/X11/XF86Config.slackware /usr/X11R6/lib/X11/XF86Config Fatal Server error: No config file found! ...
—Fazli Yusof, firstname.lastname@example.org
You have not set up X on your system; it is installed, but not configured. A good way to get started is to run xf86config. This program will step you through several questions and then set up a simple XF86Config file that should get you up and running quickly. Once you get X running you can make any other changes you might need. —Chad Robinson, email@example.com
I want to upgrade my kernel. The one I am currently using is a few years old. Can I upgrade all the way to 2.0 or 2.1? One of the things I need in a new kernel is support for the CMD 640 chip. Right now, Linux can see only one of my hard drives. I am also looking for something that will play audio CDs from my NEC 260 2X CD-ROM. A few more specifics: I downloaded kernel 2.0.33 (I think). It has the support for the CMD chip. I can get all the way through make config, but then I get errors when trying to compile the kernel. It tells me I need gcc 2.6.3 or above. I got 2.7.2 from an FTP site and installed it along with the current libraries. However, now when I type gcc, it says it cannot execute the binary file. What's up? —Jim Coonradt, firstname.lastname@example.org
A lot has changed since your system was brought up. Linux went through three binary formats (a.out, elf/libc5 and elf/libc6 aka glibc). There is a lot to fix and upgrade on your system to get a recent kernel to compile and run properly. If you are interested in doing so, you can look at /usr/src/linux/Documentation/Changes/ on a recent kernel, and learn about the three binary formats, but be prepared to do a lot of reading. A much easier alternative is to back up your user data, and install a brand new Linux distribution. If you are interested in running 2.1 and the upcoming 2.2 kernels, you should consider installing Red Hat 5.2, Debian 2.0 or higher, or SuSE 5.3. —Marc Merlin, email@example.com
The date on my Linux box is not correct. My time is GMT+5. I set the universal time so it starts by subtracting five hours from it. My current date shows this:
# date Sun Jan 3 05:17:39 GMT+5 1999 # date -u Sun Jan 3 10:17:43 UTC 1999
—Bilal Iqbal, firstname.lastname@example.org
To set the timezone, you should make the following symbolic link:
ln -s /etc/localtime /usr/share/zoneinfo/US/Pacific
To set the time, you can do it relative to UTC or your local time; it depends on what time you stored in the BIOS' clock. Read the man pages for hwclock (or clock if the first doesn't exist) for more information. —Marc Merlin, email@example.com
When I use TELNET to log in to my system, I cannot log in as root (I get the login incorrect message). However, I can log in as myself and use su to become root using the root password. What's up? —Scott Hall, firstname.lastname@example.org
The file called /etc/securetty defines the terminals a root user may log in to. Make sure ttyp0, ttyp1 and so forth are defined in that file. Each TELNET session uses one of these terminals, so define several. If you don't and normal users are logged in on p0 and p1, you will not be able to log in as root on p2. —Chad Robinson, email@example.com
TELNET is set up to deny root access as a deliberate security measure. This keeps a cracker from compromising the root account directly—he has to first compromise a user account, thereby making it twice as hard to become root on your Linux box.
Incidentally, the potential cracker's job is made even harder by not indicating that no password will work for root when logging in remotely. The cracker can't tell whether his login attempt is failing because he has the wrong password, or because remote root logins are entirely disabled. —Scott Maxwell, firstname.lastname@example.org
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.
Free to Linux Journal readers.Register Now!
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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