Ask Klaus

Ask Klaus

Article from Issue 160/2014

Klaus Knopper answers your Linux questions.

Video Woes

Klaus: I have recently installed Fedora 20 on a Pentium 4 with 1GB of RAM and a Ti4200 video card. I can't seem to get the video sorted out. Your Knoppix 7.04 works perfectly. I wonder what video drivers you are using? The best I can get out of Fedora is 1024x768, but your 7.04 gives me a perfect 1280x1024 @75Hz resolution. Xrandr in Fedora doesn't show the proper resolutions, but yours in 7.04 does. Thanks in advance for any advice you might have. Ron

Answer: You can find out which graphics card drivers Knoppix (or any other distro) uses by looking for the graphics-related kernel modules and Xorg plugins in use. Check the output of lsmod for the "nouveau" driver and look into /var/log/Xorg.0.log to see which driver is active in Xorg.

If Xorg cannot find or activate the proper accelerated driver for your graphics card in Fedora, it will try the generic VESA or framebuffer module. Both of these will not be able to handle changing resolution via xrandr and most likely will not even give you the perfect resolution unless an optimized framebuffer kernel module exists for your graphics card.

To get best support for your Ti4200 graphics card (NVidia code name NV25 [1]), you will need:

  1. A relatively new kernel (especially the nouveau module).
  2. Xorg server 7.7 (core 1.12) and the matching nouveau video module version 1.0.1 or later.
  3. libdrm-nouveau (1a or 2) matching the above.
  4. The Mesa DRI package, which may be "experimental" depending on the distribution: libgl1-mesa-dri or libgl1-mesa-dri-experimental.

It must be noted that it is crucially important that the versions of Xorg, the nouveau kernel and nouveau Xorg module, and the DRM and DRI packages play nicely together, which is usually the case if you install all of them from the same development branch (for Debian, I usually use the "unstable" and "experimental" branch for all graphics hardware support packages and drivers).

The proprietary driver also is available from NVidia, but it should not be necessary to use it if the free nouveau driver works fine on Knoppix 7.0.4.

If you find that all needed packages are in fact installed in Fedora (double-check for the newer nouveau drivers), there can still be a problem actually loading the nouveau kernel module, related to the vesafb driver needed to display a "splash screen" in Fedora. For some accelerated kernel graphics modules, activation of the high-resolution vesafb during boot will prevent the nouveau driver from claiming the framebuffer and switch to fast mode. In this case, just kill the framebuffer splash screen by trying the kernel options:

video=vga16fb:off vga=normal

With these options, you should get plaintext messages during the startup process instead of the splash screen, but as soon as the nouveau driver is loaded, the resolution will switch to the "native" resolution of graphics card and monitor, and Xorg should be able to use the accelerated driver again. Also, check whether /etc/grub.conf or /etc/default/grub includes the Fedora-specific rhgb kernel option. If it is present, please remove this keyword and run grub2-mkconfig as root, then reboot Fedora.

Linux on Mac

Hi Klaus, I have a question on how to install Linux on a Mac. What is an easy way to install Linux on a Mac, and what web pages will show, step by step, how to do this? Thanks, Jesus

Answer: Depending on the Mac hardware you have, different Linux distros are available. For Ubuntu, you can find an overview with links to the installation procedure for MacBook [2] and MacBook Pro [3] in the online documentation.

To just test an Intel Mac for hardware compatibility, you can use the Knoppix "boot-only" CD, which contains only the Mac-compatible "El Torito" bootloader and the Linux kernel. Hit Cmd+C after turning on the Mac for the CD boot choice (you also have to do this when you install a Linux distribution from DVD). After the kernel and initial ramdisk are loaded, in the Knoppix "boot-only" version, the system will search for and transfer control to a previously installed Knoppix USB flash disk. In this mode, there is no trouble with the Mac's EFI boot system, as opposed to directly booting from USB. Booting from the full DVD version is possible, too, of course.

The Tuxation website [4] also contains more technical in-depth information about partitioning and interoperability issues, but for a simple Linux installation on the Mac, you will probably not need this information unless you plan to run Linux in dual-boot mode, keeping the old OS X system and repartitioning the hard drive.

New Life for Old Laptop

Hi Klaus: In issue 150 [5], you dealt with my query about getting Knoppix to boot on an old laptop with faulty BIOS. There was further mention of this query in issue 157 [6].

So, here's what happened. I first followed your suggestion about installing to hard drive using the flash installation. Well, that worked fine, although it didn't really give proper warning it would delete the Windows partition. No matter – the intent was to "upgrade" to Linux anyway!

Then, I decided if you had designed Knoppix for ReiserFS, I had better install on ReiserFS. So, I repartitioned the drive, loaded Knoppix on partition 1 and then Ubuntu on partition 2 with Ubuntu's version of GRUB. The latter evidently has the necessary BIOS routines to respond to keyboard input, and I can now select Knoppix and boot successfully. (I also included a 2GB swap partition).

Knoppix is pretty nifty on the old machine (Acer Travelmate 345T with Pentium 3 CPU, 256MB RAM), but I wonder if you can recommend a lighter, faster web browser. It must still be Java enabled since my goal is suitably nerdy – i.e., play chess on! Opera (which I downloaded) seems to work pretty reasonably for ordinary browsing but more or less dies when I select "play live" on I don't know what the system overheads are for this type of gaming client and all the ads that accompany it.

Finally, in respect to clock sync on reboot (because of the faulty BIOS), I discovered the client ntpdate, which works fine. It was just a mission to install – may I suggest that you include it as a standard part of the Knoppix distro? I did actually buy a new battery (as your reader suggested in issue 157) but that doesn't solve the BIOS problem – BIOS is dependent on the CMOS battery, which has died and seems impossible to replace.

Many thanks for your response to my query – I look forward to further use of my old laptop with Knoppix installed.

Regards, Neil

Answer: Congratulations on giving your laptop a new life with Linux. Concerning the overwritten Windows installation: I'm quite sure that the Knoppix flash installer warns you before repartitioning and formatting the drive and tells you that "all data will be lost."

Anyway, about the CMOS battery: That one is actually the one I would replace. On some boards it is just a CR2032 "button cell," which is inserted into a special socket or soldered onto the board [7]. In the first case, it is easy to replace the battery after you found it, but in the second case, it is more dangerous to remove it and set a new one in place.

If you want to start ntpdate <time server> automatically in Knoppix, you can add the command at the end of /etc/rc.local before the final exit statement; it will then be called as root during system startup.

About web browsers: Yes, Firefox tends to consume a lot of RAM, but using the Knoppix zRAM feature, it might not be too heavy, even for old computers. However, the browsers Midori [8] and Epiphany (built in to the Gnome 0 desktop) might consume somewhat less memory, and they support the IcedTea Java plugin for running applets, although not every version may be compatible.

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