Notes

Num-Lock am Notebook

Tuesday, August 21st, 2007

Wenn Sie sich wundern, dass die interne Tastatur Ihres Notebooks plötzlich viele falsche Zeichen liefert, nur weil Sie zwischendurch mal eine externe (USB-)Tastatur angeschlossen hatten, dann ist sehr wahrscheinlich Num-Lock aktiviert. Das lässt sich beheben, indem Sie einfach die Num-Lock-Taste noch einmal betätigen. Diese ist auf Notebooks selten direkt vorhanden, stattdessen ist dort der Status über eine Tastenkombination der Art Fn + Num-Lock oder Fn + NumLck oder Fn + [Taste mit Schloßsymbol und darin abgebildeter Ziffer] umschaltbar.


Debian Etch on Samsung R40 Aura

Sunday, June 17th, 2007

Yesterday I got weak for a moment and purchased a Samsung R40 Aura C430 Corin notebook. It is the lowest performer in a low-budget series of consumer notebooks from Samsung with a Celeron M430 processor at 1.73 GHz, 1 GB of RAM, a 120 GB harddisk and a DVD dual-layer burner for 600,- €. But still it offers all the power and features that I need to run my Debian Linux desktop. Inevitably the box also includes a copy of Vista Home Premium which I do not plan to use.

After finishing the Debian installation, there were some steps left to get the X server and WLAN connection running. Initially the X server failed to start in vesa mode with a no screens found error message. The graphics adapter is an ATI Radeon Express X1250 which uses either 128 or 256 MB of shared memory (depending on your BIOS setting) and the appropriate drivers are available in Flavio Stanchinas ATI Linux driver packages. See his website for detailed instructions.

$vi /etc/apt/sources.list
[...]
deb ftp://[...]/debian/ stable main contrib non-free
deb-src ftp://[...]/debian/ stable main contrib non-free
[...]
deb http://security.debian.org/ stable/updates main contrib non-free
$aptitude update
$aptitude install fglrx-control fglrx-driver fglrx-kernel-src
$module-assistant prepare
$module-assistant a-i fglrx
$modprobe -v fglrx
$vi /etc/X11/xorg.conf
[...]
Section "Module"
        [...]
        Load    "dri"
        Load    "GLcore"
        Load    "glx"
        [...]
EndSection

Section "Device"
        Identifier      "ATI Technologies Inc ATI Default Card"
        Driver          "fglrx"
        BusID           "PCI:1:5:0"
        Option          "VideoOverlay"  "on"
        Option          "OpenGLOverlay" "off"
        Option          "UseInternalAGPGART"    "no"
EndSection

Section "Monitor"
        Identifier      "Generic Monitor"
        Option          "DPMS"
        HorizSync       28-49
        VertRefresh     43-60
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "ATI Technologies Inc ATI Default Card"
        Monitor         "Generic Monitor"
        DefaultDepth    24
        SubSection "Display"
                Depth           24
                Modes           "1280x800" "1024x768" "800x600" "640x480"
        EndSubSection
EndSection

[...]

Section "DRI"
        Mode    0666
EndSection

Restart, and that should be it for the X server. You can find the ATI Control Panel on Desktop -> Administration.

Concerning the WLAN with Atheros chipset you should read C. Pilka’s howto on slashconcept.com. After installing the appropiate packages, creating the modules with the module assistant and doing a reboot, I just configured the wireless connection with the NetworkManager Applet in Gnome.

$aptitude install madwifi-source madwifi-tools \
madwifi-doc wireless-tools wpasupplicant
$module-assistant a-i madwifi

Btw: I’m not yet sure, but maybe I’ll return the notebook next week. Actually the R40 works good and as expected for the price, but the display has such a narrow vertical viewing angle that you may soon get tired of permanently either moving your head up and down or tilting the screen back and forth for the best view. See also this PC Pro review.


OpenVZ VPS configuration samples

Sunday, December 31st, 2006

Sample A
Hoster runs Virtuozzo on a Dual Core Opteron 175 CPU / 4 GB RAM with 32-bit SMP kernel and probably dozens of virtual hosts. First impression of delivered performance is ok, but scant resources make it almost unusable for even basic server tasks. To me this is more a “jailed” environment to host a few static websites. Guaranteed memory of 90 MB per VPS.

resource        barrier      limit
----------------------------------
kmemsize       20971520   23068672
lockedpages         256        256
privvmpages       65536      72192
shmpages          20480      20480
numproc              96         96
physpages    2147483647 2147483647
vmguarpages        8192 2147483647
oomguarpages      23040 2147483647
numtcpsock          360        360
numflock            188        206
numpty               16         16
numsiginfo          256        256
tcpsndbuf       1720320    2703360
tcprcvbuf       1720320    2703360
othersockbuf    1126080    2097152
dgramrcvbuf      262144     288358
numothersock        360        360
dcachesize      3145728    3460300
numfile            4096       4096
numiptent           100        100

Sample B
Hoster runs Virtuozzo on a Pentium 4 CPU at 2.4 GHz / 1.5 GB RAM with 32-bit kernel and probably a handful of virtual hosts. First impression of delivered performance is ok and second impression is too, well configured and performing. This is the hoster and configuration that this website is currently running at. Guaranteed memory of 515 MB per VPS.

resource        barrier      limit
----------------------------------
kmemsize       14112433   15523665
lockedpages        7600       8192
privvmpages      238528     259324
shmpages         262144     262144
numproc             396        396
physpages             0 2147483647
vmguarpages      132062 2147483647
oomguarpages     132062 2147483647
numtcpsock         1000       1000
numflock            400        464
numpty              128        128
numsiginfo         1024       1024
tcpsndbuf       5366512    8204912
tcprcvbuf       5366512    8204912
othersockbuf    3006464    8126464
dgramrcvbuf      480000     524288
numothersock        764        764
dcachesize      5023656    5672656
numfile           12864      12864
numiptent           256        256

Show nonpresent devices to remove unneeded drivers

Saturday, December 23rd, 2006
cmd
set DEVMGR_SHOW_NONPRESENT_DEVICES=1
devmgmt.msc

(see http://www.heise.de/ct/06/26/006/)


OpenVZ kernel on Manitu Rootserver M / Debian

Saturday, December 23rd, 2006
#aptitude install wget bzip2 patch libncurses5-dev
#cd /usr/src

#wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.9.tar.bz2

#tar xvfj linux-2.6.9.tar.bz2

#ln -s linux-2.6.9 linux

#cd linux

#wget http://download.openvz.org/kernel/...\
      /patch-023stab037.3-combined.gz

#gzip -d patch-023stab037.3-combined.gz

#patch -p1 < patch-023stab037.3-combined

#wget http://download.openvz.org/kernel/...\
      /kernel-2.6.9-023stab037-i686.config.ovz

#cp kernel-2.6.9-023stab037-i686.config.ovz .config

#make bzImage

#make modules

#make modules_install

#cp arch/i386/boot/bzImage /boot/bzImage-2.6.9
#vi /boot/grub/menu.lst
title           Linux-2.6.9-openvz
root            (hd0,1)
kernel          /boot/bzImage-2.6.9 root=/dev/sda2
savedefault
boot
#shutdown -r now