Linux tips collection Collection of linux tips and tools

warning: rtl8185 (Realtek Semiconductor PCI) wireless

The biggest problem was the fact that I need to restart the computer several times before a connection to the AP was possible. There were no errors or warning, it just asked all the time for a password.

When the connection was successfully established there were mini-lags, that means the connection timed out for some seconds. So live streaming or voip was not possible.

So I change to the driver provided directly by Realtek, r8185b is the module name.

First I thought, year its working now, signal strength was very good displayed, not so much radio noise like with the kernel driver.

But..

• Connection speed was very bad, I have a 20 Mbit/s DSL connection, over the wlan I only got 200 kb/s
• Asked for the WPA2 Password more then 10 times before a connection was possible
• Too connection timeouts

So I tested the whole shit with my netbook. In the same room with the same distance, at the same position:

• No connection problems
• No timeouts
• Average signal strength

Ok, I went to buy a repeater for the wireless signal. Hoped it would fix the realtek problem.
Nothing changed at all, so I flashed the repeater with an OSS-Firmware and configured it as a client adapter.

Connected it with a good old Ethernet cable to the computer, put out the rtl8185 and all problems were gone.

It seems I got a very bad card or the chip set is simply not usable with linux. Better you don’t buy this chip set, you will only lose time.

StartSSL (Startcom) SSL Certificates with Zimbra 6.x

Step by step guide:

1. Create the private key and certificate with StartSSL
2. Download the ca bundle
   wget https://www.startssl.com/certs/ca-bundle.crt
3. Copy the private key to
   /opt/zimbra/ssl/zimbra/commercial/commercial.key
4. Deploy ca bundle
   /opt/zimbra/bin/zmcertmgr deployca /path-to-ca-bundle/ca-bundle.pem
5. Copy the ca bundle to:
   /opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt
6. Add ca bundle to the keystore
   /opt/zimbra/java/bin/keytool -import -alias new -keystore /opt/zimbra/java/jre/lib/security/cacerts -storepass changeit -file /opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt
7. Verify key and certificate
   /opt/zimbra/bin/zmcertmgr verifycrt comm /yourpath/commercial.key /yourpath/commercial.crt
8. Deploy certificate
   /opt/zimbra/bin/zmcertmgr deploycrt comm /yourpath/commercial.crt /yourpath/commercial_ca.crt
9. Restart zimbra
   /etc/init.d/zimbra stop
   /etc/init.d/zimbra start

Sources:

http://wiki.impressive-media.de/doc/eigenes-zimbra-ssl-cert-mit-startcom-startssl-2048

http://www.zimbra.com/forums/installation/38285-can-t-install-ca_cert-certificates-2.html

Abroad with Ruby – How to fix broken imap strings

As I programming at the moment a ruby on rails imap client (still waiting for support of my 5xxx GPU), I had today some troubles with broken text encoding.

My problem was “=?utf-8?Q?”.
When we have a look at a simply mail and the header of it, we see that things look like:

Subject: =?utf-8?Q?AW:_Frage_bez=C3=BCglich_R=C3=BCckf=C3=BChrunge?=
=?utf-8?Q?n?=

viel eigenkreativit=C3=A4t, sch=C3=B6pferisches

Nice, isn’t it?
So after searching around the ruby documentation I found what I’m looking for:

——————————————————— String#toutf8
String#toutf8 -> string
———————————————————————–
Convert self to UTF-8Note This method decode MIME encoded string and convert halfwidth katakana to fullwidth katakana. If you don’t want it, use NKF.nkf(‘-wxm0′, str).

Now the strings are readable. And no, I don’t know why this is working (katakana is a Japanese lettering).
For any hints I’m very thankful!

The solution is:
class LoginController < ApplicationController
require 'net/imap'
require 'base64'
require 'mail'
require 'iconv'

def connect
@mail = Mail.new
@mail_subjects = Array.new
@mail_subjects2 = Array.new
@string = String.new
@string2 = String.new

end
end


end

OSS Radeon driver the easy way with arch linux

Like you heard there is a opensource driver for the the radeons gpu’s (till r700 series).

With the release of the 2.6.32 kernel the driver runs very well and with the kms of course!

The main problem is to get the whole mesa stuff installed, for this I created a simply script that updates all from git, so that you can enjoy it!

export build_path="your-path-here"

cd $build_path/xf86-video-ati-git
makepkg --asroot -f
pacman -U xf86-video-ati-git-$(date +%Y%m%d)-1-x86_64.pkg.tar.gz

Simply add the build_path and run the script as root (I know not a very good way, but I do not like sudo).
The packages you find in the aur archive.

Attention: I use the radeon driver, if you want to use the radeonhd driver you must replace the last block in the script.

openoffice.org icon problem/graphic glitches

If you are using KDE4 with the gtk-qt-engine you may have the problem that the icons are not displayed and/or there are some graphic glitches.

To fix this you need to export:

export SAL_GTK_USE_PIXMAPPAINT=1

Simply insert this line somewhere in /etc/profile.

ATI Catalyst and xinerama (xrandr) dual head setup (with crossfire if you wish)

UPDATE for Crossfire- and X2-Users!

With Catalyst 9.7 you can now use xrandr.

UPDATE for Crossfire- and X2-Users!

After some testing I found some bugs with the ATI driver and crossfire.

1. Crossfire and dual head with X2 cards
   When you’re using Crossfire with an X2 card card and configuring dual head, the crossfire support will be disabled.
   You can find this information with cat /var/log/Xorg.0.log | grep CF
   Note: It seems that with enabled CF the dual screen setup will only work in cloned mode!
2. Crossfire and dual head with two ATI cards
   This will cause following error message in Xorg.0.log, maybe crossfire support is disabled?!
   The CF ribbon is not connected
3. ATI Catalyst 9.5 with X2 Cards
   The new Catalyst driver 9.5 is not working with an ATI X2 card. So use 9.4 until this is fixed.
4. X2 with dual head
   If you want to use xrandr with your X2 card, you can use the first part of the howto. If you get an error about some missing adapater try following
   aticonfig --initial=dual-head --adapter=all -f

____________________________

This blog entry will show you, how you can use a dual head setup with an ATI GPU. The first part is for a xrandr setup with a normal GPU without crossfire.
The second part will show how you can use a dual head with crossfire activated.
The used driver for this was ATI Catalyst 9.4.

Note: This was only tested with (k)Ubuntu Jaunty, under Gentoo and Arch Linux I got kernel panics.

General information:
First of all, ATI ships the catalyst driver with xinerama support, but this support is broken since xrandr is the default command to change screen behaviour.
So don’t try to use xinerama, it simply sucks and your kernel will crash.

Preparation:

• Clean up your xorg config file (/etc/X11/xorg.conf)
• Remove everything with screen configuration or virtual screen settings, you only need the fglrx stuff.
  Best way to do this is simply to create a default config with dpkg-reconfige xserver-xorgand get the fglrx stuff with ati-config --initial -f
• Add the virtual desktop size into the new xorg.conf, you need to copy this into your “ScreenSection” (not for crossfire users)

SubSection “Display”
Depth        24
Virtual              3840 1080 # x y resolution of both screens!
EndSubSection

This will create a virtual desktop with a width of 2×1920 (3840) and a height of 1×1080. Note you must calculate these values.

Let’s move it (the xrandr way):

• Run following command

xrandr --output your_first_screen --mode your_resolution --output your_second_screen --mode your_resolution --right-of your_first_screen>

Let’s do it (the crossfire way):

Note: It’s was a very painfull way to get an ATI x2 GPU running (lost one night through this), so this will show a clean way to set up the xorg.conf and all needed aticonfig stuff.

• Create a crossfire chain
  aticonfig –cfa –adapater=all
• Setup pairing
  aticonfig –add-pairmode=<your width>x<your height>+<your width 2>x<your height 2>

Now you can change screen behavior over amdccl.

Use VirtualBox’s snapshot system like VMWare’s

This is a short HowTo for using VirtualBox’s snapshot system like you use it in VMWare Workstations.

1. Go to your VirualBox config folder and browse to your machine
   cd ~/.VirtualBox/Machines/<your machine name>
2. Get a list of the snapshots
   cat <your machine>.xml | grep “Snapshot uuid”

   <Machine uuid=”{e379cecf-54be-4dd5-8563-5fdfe1fff994}” name=”W7RC1″ OSType=”Windows7_64″ lastStateChange=”2009-05-05T19:18:49Z” currentSnapshot=”{b32f283d-ff08-4335-a7ad-1414eeaa922b}” currentStateModified=”false”>

3. Change to a snapshot
   - Open the <your machine>.xml file
   - Go to the 4th line and change the value for the attribute “currentSnapshot” to the hash of your preferred snapshot.
4. Start the Machine
   - Maybe optional: Start the VirtualBox GUI and discard the machine state if available
   - Maybe optional: Go to the snapshot tab and right click the snapshot you added to uuid and select “Discard Snapshot”
   - Boot your machine
   You can repeat these steps every time you want to switch to another snapshot.