Best of Technical Support

Our experts answer your technical questions.

AOL for Linux?

I have a dual-boot (GRUB) setup with Red Hat Linux 9.0 on one partition and Windows XP Professional on another. I also am running AOL 9.0 broadband software for my ISP. Is there a driver for the AOL Broadband Blaster modem that I can use to run Red Hat 9.0 with Internet services through my AOL broadband connection? I want to avoid changing Internet services and buying a new DSL modem, but I can't get Red Hat to see the Broadxent modem, and Linux doesn't recognize my AOL broadband software.


Natosha


NZimardo@aol.com

You cannot run AOL's software under Linux, so you will not be able to access AOL services through traditional means. However, for general Internet access, many Broadxent DSL modems have both USB and Ethernet interfaces. If you can switch to the Ethernet interface and install an Ethernet card in your PC, you should be able to access the Internet from both operating systems. If your DSL modem does not have an Ethernet interface, you need to replace it with either a USB device that Linux supports (such as from Alcatel or ECI) or a device with an Ethernet interface. If you cannot get AOL to agree to allow you to do this, you should consider an alternate service. Linux desktop deployments are becoming more common today, especially with the efforts of Lindows and other distribution vendors working with retailers to package their products into inexpensive solutions.


Chad Robinson


crobinson@rfgonline.com

Collecting the Ultimate Linux Box

I have followed Glenn Stone's “Ultimate Linux Box” series on the Web and in print and decided to build my own version. I have found the economical way is to build it piece by piece; I buy a piece every month and put it away until I get all the pieces, then I'll put it together. After doing a lot of research I came to the conclusion that 1) modular is the way to go, and 2) 64-bit is the future. I have thus elected to build an AMD Opteron single CPU system running Mandrake Linux, 9.2/64. I am thinking of buying the ASUS SK8N Motherboard (2GB of RAM, twin Maxtor 120GB SATA HD, 3.5 floppy, 5.25 floppy (legacy work), CD-RW (48x12x48x) and, with luck, a DVD player. Is this a problem board on Linux? If it really is a problem board, can you suggest a solid alternative board I could buy?


S.W. Bobcat


swbobcat@hotmail.com

If you have problems with this motherboard, it is more likely to be a driver support issue than anything else. Most board-related issues can be resolved with simple workarounds, such as the noacpi boot option. This motherboard in particular was used in several SPEC.org benchmark tests in 2003, so I doubt there is an issue that cannot be resolved in some fashion.

However, I would advise you to consider your 64-bit choice carefully. Unless you are doing some serious rendering or mathematical computation, the 64-bit platform is unlikely to provide you significant benefit. In fact, you may find that some applications run slightly more slowly; many benchmarks today are showing that unless a workload is optimized for a 64-bit platform, it does not perform to its full ability. 64-bit computing ideally is suited for a variety of computational workloads or for things that require wider integers for indexing facilities, such as databases. Descent 3 won't run any faster.

There is no question that many environments can benefit from this change, as long as you recompile everything to support it. Is yours going to be one of these? On the other hand, the Opteron itself is a great processor, and if you are making the choice based on HyperTransport, for instance, then kudos!


Chad Robinson


crobinson@rfgonline.com

I'm afraid, I can't agree with your modular assertion. PCs have become so complex that you take the risk of ending up with incompatible chipsets or a system with subtle bugs. This doesn't mean you will, but as PCs have become more than a thousand times faster, the mix-and-match approach is a lot more likely to hit some subtle timing incompatibility between two components. As for 64-bit being the future, yes, although you are not likely to need 64 bits for what you are going to do. A wait-and-see approach for 64 bits wouldn't be unreasonable in your case (and in the meantime, you could buy a 32-bit system). In addition, you will not end up with a working system before you buy and assemble the last piece, and even then, it's only if you are lucky and everything does piece together. You will not only pay more for all the components bought separately, but the price of the first components you bought will have dropped by the time you buy the last one. I really recommend that you buy a prebuilt system unless you are really looking to do hardware tinkering and are ready to swap components and meet potential incompatibilities.


Marc Merlin


marc_bts@google.com

It's better to save up for the parts and buy them all at once. That way the warranty for the first part isn't ticking away while you collect the rest. And, as Marc points out, PC hardware does tend to get cheaper over time. If you're building your own Linux system, explore the Web sites of Linux system vendors and see what hardware they use. It's likely to be stable and compatible.


Don Marti


dmarti@ssc.com

How to Use #include

I am trying to access ports using check_region() . I have included the file /linux/resource.c to do this. But when I try to compile the program, I get the following error:

In file included /usr/include/linux/sched.h
                     /linux/resource.c
/usr/include/linux/timex.h :field "time" has incomplete type

where time is of type struct timeval declared in the file timex.h.

Kindly tell me the possible reason and its solution.


Ashutosh Sharma


catchwavesin@yahoo.com

resource.c is a source code file that contains all of the function implementations, including the one you are trying to use. I believe you should be including <linux/ioport.h> instead, which contains the definitions for these functions, not the implementations.


Chad Robinson


crobinson@rfgonline.com

Big Pictures from The GIMP?

I use The GIMP for almost everything in picture editing, and I have created some large pictures, say 24 × 24 inches. I basically use them as first-draft examples before finally painting my subject on canvas. I have an HP 5650 printer that obviously cannot print such large paper sheets. So the results are that only the upper-left corner of the picture is printed out. What I'm looking for is the ability to print the entire picture in its correct size but spread out on several 8 × 10 sheets of paper that I then can paste together to create the correctly sized pictures. Does any such software exist in the Linux world, or must I purchase HP's Plotter to achieve this result at a greater cost?


Paul Godin


linuxstuff@istop.com

Perhaps I'm confused, but your problem sounds as though it has a simple solution. You simply need to crop successive sections of the image so you can print one tile at a time. You can do this manually with The GIMP. You also can create a script to do this automatically, using the ImageMagick toolkit. There is a tool called convert(1) in this suite that not only allows you to convert images to a format more suitable for printing (such as PostScript or PCL) but also to crop portions from the image. See the man page for this application for details, but I believe you probably want to use the -crop option.


Chad Robinson


crobinson@rfgonline.com

You can print your file in PostScript and then use this program to split it onto multiple pages: www.ctan.org/tex-archive/support/poster. It also prints the marks you need to cut the pages and paste them together.


Marc Merlin


marc_bts@google.com

What you are trying to do is called a mosaic. There are many tools to do mosaics with The GIMP; take a look at registry.gimp.org. Also, bear in mind that your printer may have blind printing areas where it is not possible to print, perhaps in margin areas, so take this into account when doing the mosaic. You also may need to do some traditional cutting on each sheet of paper.


Felipe Barousse Boué


fbarousse@piensa.com

Making Red Hat 9 into a Firewall

I am trying to set up a box as a firewall so routing is enabled. I have two Ethernet cards for this box. I am running FWbuilder 1.1.1 on Red Hat 9. My question concerns the kernel route tables. The situation is the external address is on eth0 192.168.1.2, and the internal address is on eth1 172.10.10.252. My default gateway on eth0 should be 192.168.1.1; however, the kernel makes the default 192.168.1.2 and will not release this route. This now has routed to the 192,168.1.0 side, but it stops at eth0 and cannot find a way to 192.168.1.1. The internal side works great, though. Besides rebuilding the kernel, how can I set the default gateway to be 192.168.1.1?


Joe Golden


jgolden3@csc.com

Edit the /etc/sysconfig/network-scripts/ifcfg-eth0 file and add a line like GATEWAY='192.168.1.1', and then restart your network with the service network stop/service network start commands or reboot your machine. This fixes the default gateway route of the eth0 card to 192.168.1.1.


Felipe Barousse Boué


fbarousse@piensa.com

Switching between Running X Sessions

How can I have multiple X sessions running at the same time? That is to say, if I'm logged in as root and also log in on Ctrl-Alt-F2 and give the command startx -- :1 to fire up X, everything works fine. If I go back to Ctrl-Alt-F7, all is fine there too. But, when I go to Ctrl-Alt-F2 again, X has crashed there, but it still is up on F7. Is there some command that I can give so X stays up on F2 when I'm going back and forth?


Bjarni Valsson


bjarniv@hotmail.com

X does not run on F2 (pty 2). Each X instance you start creates its own pty, hence the switch to pty 7. If you go back to pty 2, you actually can put X in the background (Ctrl-Z, then type bg) and continue using that console for other tasks. If you start up another copy of X, and X already is running, it creates a new pty (now 8, in this case). You must then press Ctrl-Alt-F8 to switch to that copy of X. Remember, X is a user-space application. Two running X processes should not interfere with one another unless you are doing something odd with your hardware; certain video card driver settings might cause trouble.


Chad Robinson


crobinson@rfgonline.com

DHCP under Knoppix but Not Debian

I recently installed a Linksys WPC11 wireless card on an older Gateway 433 Celeron machine running Debian Woody 3.0. The card works fine only after I log in as root and type pump -i wlan0. I followed the instructions to the letter and even modified the specified files to read DHCP as the instructions stated. The interesting part of this equation is that I ran Knoppix on the same machine out of curiosity, and Knoppix correctly identifies the card, and it automatically gets an IP address. Any idea what I can do to make this card pull an IP automatically?


Wes Reneau


wes@rose.net

Woody 3.0 is an exceedingly old version of Debian (mid-2002), as far as Linux distributions go. You should consider upgrading to the latest distribution. Knoppix is based on Debian, but you are undoubtedly using a fairly recent version. This is probably nothing more than an issue with one of your boot scripts, but without viewing them it's difficult to tell.


Chad Robinson


crobinson@rfgonline.com

“dump”ing an ext3 Filesystem?

I regularly back up all my machines using amanda and dump. The backup is to a dds-3 tape drive on a Red Hat 7.2 machine (servred72). I upgraded a Debian 3.0 machine to sarge and had some problems. I wanted to amrestore on the Debian 3.0 machine, but amrestore requires root privilege to run. I was prevented from the restore because of security mechanisms. The appropriate amandahosts files were modified to include root. Root access was prevented in the LAN. Two questions: 1) dump works on only ext2 filesystems. Is there a newer version to support the journaling filesystems? 2) What could I do to relax security temporarily and allow amresotre to work as root across the LAN?


Alan Polinsky


polinsky@acm.org

A dump that's recent enough should work with ext3, because ext3 is ext2 with a new feature flag on the filesystem and a special hidden inode with the journal, which you can but don't need to backup. You do need to quiesce the journal when you take a snapshot for backup, but dump has support for that, as hinted by the sf.net Project page, sourceforge.net/projects/dump, which says “Dump/Restore ext2/ext3 filesystem backup”.


Marc Merlin


marc_bts@google.com

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