Linux

2.6.5

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Just upgraded Angband, my main workstation, from kernel 2.4 to 2.6.5. The upgrade went with no real problems, and everything runs really smooth. Feels quite fast too.

2.6.3

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I spent some hours upgrading Isengard, my laptop, to the latest 2.4 and 2.6 kernels. I never had any luck with the 2.6 kernels, as hardly anything worked, so I didn't expect much of the new 2.6.3 kernel. But lo and behold : I got a decent framebuffer screen at boot. I noticed some progress with the 2.6.2 kernel, where I barely saw some text scrolling by, but 2.6.3 has everything running smoothly. Except for my Xircom PCMCIA card, which freezes the laptop, but that seems to be a bug in the driver. Tomorrow, I'll give a patch a run, and see if that will solve the problem.

Greater security

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I'm not really a guy who installs every new Linux kernel, but in general I like to follow in the slipstream of newer kernels. In practice, that means I'm maximum 3 or 4 kernel releases behind (I tend to follow the 2.2 kernel branch too). So now that Linux-2.4.23 has been released this weekend, and that my firewall was happily running 2.4.20, I decided to upgrade the box to 2.4.23. I wanted to increase significantly the security, by patching the kernel with the grsec patch, aka GReater SECurity. It's a modification in the line of big iron Unices, where the kernel is provided with ACLs, several randomizer like PIDs, auditing and security restrictions. I still have some tweaking to do, like tightening the kernel module loader, but in general, I'm quite satisfied with the result.

Linux 2.6 and VMware

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Linux 2.6 is almost here; there are still some issues with VMware and Nvidia drivers, but these wil be fixed soon (I'll guess VMware will release their part after the official 2.6 announce). In the meantime, follow this procedure for VMware :

VMWare works fine in 2.6, given that you install the updates at http://knihovny.cvut.cz/ftp/pub/vmware/. Just get vmware-any-any-update45.tar.gz and run the install script. Then re-run vmware-config.pl. Make sure that your 2.6 kernel doesn't have preempting enabled (this can cause some crashes) and you're all set.

The great package management battle

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Ladislav Bodnar compared different package management systems on the major Linux distributions out there, like apt-get, urpmi and yum. Debian is the overall winner, but Mandrake's urpmi had some very good points too. Interesting quote about Redhat/Fedora : Although yum is now in rawhide, I don't expect to see it in a released version of RHL or RHEL. Why do I say this? Because the newest up2date that will ship with the upcoming RHEL and RHL now supports remote "yum" and "apt" repositories in addition to the native "rhn-style" repositories. Since up2date now speaks all languages (rhn, apt, yum) there is no need to ship those other tools.

Linux rescue CDs

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A coworker of mine accidentically destroyed his laptop filesystem with a Windows XP - Redhat dualboot. It booted into the Grub console, where it sat dead, as apparently Grub could not read its config file. The Linux filesystem was toasted, and eventually we used a Knoppix CD as a rescue system (very impressive !) to recover some of its files on the XP partition.

I allways used Tomsrtbt as a Linux emergency system, but as it has to fit on a floppy, it has rather harsh choices to make about the available programs. RIP Linux, which stands for Recovery Is Possible, is a nice bootable CD recovery Linux system with some fancy utilities to recover Linux and Windows files. Unfortunately, it doesn't contain Vim, but the rootfs can fairly easy updated with the binaries of your choice (that is, if you compile them onto it). A perfect Linux rescue CD, however, would be a crossing of RIP Linux and Debian, with a bunch of utilities to add your favourite programs. Which means I'm still having another look around for such a system.

Linux-2.4.22

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I upgraded lately to Linux-2.4.22, and I don't know why, but my whole desktop is kinda feeling sluggish. DVD playback is bumpy, and Mozilla feels like a whale. Weird, because the last kernels I used, 2.4.18 and 2.4.20, were really great in terms of performance. Maybe it's time to look for those preemptible and low-latency patches again...

Update : when playing a DivX, I got a load of 7, so I knew something was wrong. DMA access bailed out with a Operation not permitted. Seems that somehow VIA block device support was left out. Much smoothly now !

SCO vs Linux

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A group of Australian techies have put together an analysis matrix\r\nof the likelyhood of each SCO Unix claim being true, and what outcome would most likely result if so. You will notice that the purported decision matrix (implying a logical document with conclusions deduced by scientifc logic from given hypotheses) says at the bottom of all possible outcomes 'linux is unaffected'.

In case you hadn't guessed, this is far from the logical document the name suggests, but really a portrayal of one person's viewpoint. The conclusion, namely that linux is unaffected in all cases is probably false, as I can think. Not because Linux contains some intellectual property of SCO - that statement is false - but because of the fear, uncertainty and doubt which has been seed. IBM will probably stretch this lawsuit out over a year, to let SCO bleed as much as possible. Alas, the damage to Linux may already have been done, in the way that many managers will be reluctant to deploy Linux.

Adventures in Linux

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Last week has been in the focus of playing with Linux. I installed a proxy masquerading firewall for a collegue, based on the Alcatel USB SpeedTouch modem, using the Open Source drivers of Benoit Papillault. It took some time to properly tuning the stability of the modem driver, but in the end, I managed to get a very stable box. It was based on Debian, of course. Unfortunately the stable Debian release, which new version is imminent... for several months now. As a result, stable has become archaic with its 2.2 kernel. I upgraded to a 2.4 kernel for USB support and used these pages to install and configure the modem. If you want to do the same, I advise you to use the 20011007 drivers (with pppoa3) and this HOWTO for the ppp setup.

After that, it was my machine's turn. First off all, I decided to fix the side effects of my unstable NVidia drivers, and upgraded my filesystems to ext3. Then I upgraded my NVidia drivers, only to found out that they were as unstable as the earlier release. Well, at least, ext3 was doing its job ;) I Googled a bit around, to found out that the following setting may be the solution : just add

Option "NoRenderAccel" "on"

to your XF86Config-4 file, and the crashes should be history. Looks like that fixes everything...

It is unbelievable how performant the Low Latency patch is for Linux desktop systems. Whereas a vanilla Linux 2.4.18 kernel is horribly sluggish on my 128 Meg based system, the LL patch really boosts things up. I first tried with the PreEmptable kernel patch, as it is now default in the 2.5 kernel series, but after giving unsatisfying results, I added the LL patch too. At least, my MPlayer is now again playing without glitches, while my Seti@Home is crunching in the background.