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Our experts answer your technical questions.

Wireless Settings in Fedora

I've got my wireless NIC working in Fedora Core 2, and I'm able to communicate with the network after I configure with iwconfig. But, after I reboot, all the settings are lost, and I have to enter all the info again. Is there something I'm not doing, or is this problem something else?

Weoh G


You should use the system configuration tools to set up the device: Task Bar→System Settings→Network.

Christopher Wingert


The wireless-tools command-line utilities (iwconfig, iwspy, iwpriv) do not stick through a reboot, as you have experienced. The thing to do is to implement the settings through the appropriate configuration file. In the case of Fedora, you probably can get what you need set permanently, by adding wireless-specific options to your ifcfg file (/etc/sysconfig/network-scripts/ifcfg-ethX, where ethX is the Ethernet device name assigned to your wireless card). You simply need to place the additional wireless-related options into that file. For example, on my laptop, which connects over an 802.11b interface to the router/firewall/dhcp server I hacked together in my house, the file is very simple:


The MODE, CHANNEL and KEY options were all I needed for my setup; yours are sure to be different, but anything you can do via the command line should be available as an option in the file. For a list of all available settings, take a look at /etc/sysconfig/network-scripts/ifup-wireless.

Timothy Hamlin


The following page contains specific instructions on how to set wireless networking on the Fedora Core Linux distribution: www.siliconvalleyccie.com/linux-hn/wmp11-linux.htm.

Felipe Barousse Boué


Hunting for a Single-Board Computer

In Embedded Linux Journal, issue 9, there was an article titled “Update on Single-Board Computers” that contained a picture captioned “An EBX Form Factor PowerPC-based SBC from Motorola”. What I wanted to know is which company manufactures such a board—an EBX Form Factor PowerPC-based SBC.

Chirag Cheema


With some research, I turned up at least two options: www.embeddedplanet.com/products/rpxc.asp and www.acttechnico.com/mot-ebx-motorola.html.

Chad Robinson


Try Ampro: www.ampro.com.

Felipe Barousse Boué


Getting System Info

We have a system-defined structure called MACHINE_STATIC to find machine architecture, including the IP address, processor speed, OS and so on. I need a similar structure on Linux to extract machine architectures. Do you know if one is available?

Rajesh Kumar Patnaik


Not a structure, per se, although certain ioctl() calls can provide many of these details. But you should be looking toward the new mechanisms for extracting this information—procfs and the upcoming sysfs. Note that sysfs is new, and not many systems implement it yet. The files in /proc, when read, will provide you with many relevant system data elements. For example, /proc/cpuinfo provides CPU data, /proc/net/route provides network routes (IP addresses are in hex) and /proc/version provides the kernel version.

Chad Robinson


Tools for Disk Repair?

Does anyone know what tools are used in Red Hat 8 to find and repair disk and file problems—scandisk, scan registry?



These tools are not specific to a distribution; they are specific to a filesystem type. Like other distributions, Red Hat supports a number of filesystems, including ext2, ext3, xfs, ReiserFS and many others. The “see also” section in the man page for fsck lists the file checking utilities for the most common filesystems.

Recovery options available is a key selection criteria for choosing a filesystem in the first place. New Linux users are often baffled by the array of choices and seek guidance regarding filesystem selection. I always recommend that the availability of recovery tools be part of this evaluation.

Chad Robinson


GUI Database Front End?

I am using Red Hat 9 and SuSE 9 and really like both of them as well as OpenOffice.org software. However, I am puzzled by the fact that I cannot locate any quality database programs similar to Microsoft Access. I would like to build a database that will work on a small intranet consisting of three or four machines.

Todd Hoover


If you want an open-source product, take a look at Rekall, which was recently open-sourced by TheKompany.com. For a proprietary but inexpensive alternative, take a look at Adabas D, part of Sun's StarOffice. Both products are younger than Access and do not implement every function provided by it, so if you are looking to migrate existing databases, complex applications may not be 1:1 portable. However, both products do provide significant functionality and may be suitable for your environment, especially if your needs are more focused on new applications.

Chad Robinson


OpenOffice.org can work with almost any ODBC or JDBC database, including PostgreSQL, MySQL and even Access. Go to Tools→Options→Data Sources to set up a connection.

Bruce Byfield


I suspect you are interested in the MS Access-like user interface. For that there are many front ends for PostgreSQL, going from pgaccess, www.pgaccess.org, to OpenOffice.org's database tools that interface to PostgreSQL and other RDBMS. As a side note, tons of companies use open-source databases, from small companies with small Web sites to Fortune 500-sized companies; one special case may be the dot ORG registry that relies on PostgreSQL for managing the overall .org domain on the Internet.

Felipe Barousse Boué


If your application's interface is a simple form-based one, consider doing it as a Web application instead. You won't have to maintain software on the client, you won't have to learn different tools for internal and customer-facing applications and users already know how to use a browser.

Don Marti


Active Directory, Meet PAM

My company uses a mixture of Linux (Red Hat AS 2.1) and Microsoft Windows servers. I want to set up a central authentication server for both platforms. We use Active Directory, and it has been suggested that we might be able to use AD for Linux. Is it possible to use AD as a central authentication server for Linux, and what's the best way to do it? Or, would we be better off with a Kerberos or LDAP server?



In Linux, explore a security layer known as Pluggable Authentication Modules, or PAM. This allows you to authenticate users logging in locally against your AD servers.

For Apache, take a look into mod_auth_ldap, which allows you to do the same. Alternatively, you can use mod_auth_pam to instruct Apache to share your Linux server's PAM deployment. This is worthwhile if you do intend to have multiple applications use this data, because it will reduce your setup time. However, if Apache is your only application (and this is not uncommon) you might want to stick with a direct mod_auth_ldap configuration, as there are fewer steps involved in its configuration.

A third common configuration is Samba, and there is a good HOWTO for this configuration at this site: www.netadmintools.com/art172.html.

Chad Robinson


In the long run, you'll likely be happier with a cross-platform “single sign-on” plan based on LDAP, as described in “OpenLDAP Everywhere” in the December 2002 issue of Linux Journal. It works on Linux and Microsoft Windows and is more flexible and future-proof than a vendor-specific solution. But if you do plan to authenticate against Microsoft Active Directory using Kerberos and PAM, Tim Fredrick has some helpful notes at acd.ucar.edu/~fredrick/linux/ad.html.

Don Marti


Reader Responses

Dear Bill—I just saw your question in Linux Journal [July 2004] about setting up a Red Hat 9 and Windows 2003 server on the same PC, and I wanted to add something to the replies you already received. Namely, 128MB of RAM is too small for a Red Hat 9 or Fedora Core installation, if you use the GNOME desktop (the standard choice). You need at least 256MB of RAM for this. If you do not want to add memory (although it's pretty cheap these days), and you want to stay with Red Hat, then it is necessary to set up an alternative, lightweight window manager, like IceWM. This would involve extra trouble for a beginner on Red Hat, where IceWM does not come automatically installed.

SuSE 9.1 is a distribution that makes it easy to choose between KDE or GNOME (with heavy RAM requirements) or IceWM or other lightweight window managers. You can buy SuSE 9.1 directly from the SuSE Web site. They have a Personal edition for about $40, but it doesn't include server software. The Professional edition for about $90 does include it.

Robert Littlejohn

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