Add user in "vboxsf" group to access VirtualBox shared folder in Ubuntu guest

On Debian (Ubuntu and a like):
sudo adduser <username> vboxsf

On RedHat (CentOS):
sudo usermod -a -G vboxsf <username>

Slow boot of Ubuntu into Unity 3D with proprietary nVidia drivers

I have Ubuntu Oneiric Oncelot 11.10 with proprietary nVidia (nvidia-current: 290.10-0ubuntu1~oneiric~xup1) drivers.

And there're 2 things I'm tired of:

1. Slow boot. Mostly a black screen after nVidia drivers are already loaded.
   It turned out it lasts more then a minute (73 seconds for example, compared to booting into Unity 2D - 38 seconds).
2. Slow wake-up from suspend. Don't have precise numbers but Unity 2D wakes just immediately while Unity 3D shows me a black screen more then a minute.

So I decided to try "bootchart".
Installed it with: sudo apt-get install bootchart
And booted into:
Unity 3D - got 1:12.98 min

Unity 2D - got 0:38.66 min

Then looked if some processes related to nVidia differ in both boot logs.
And indeed I found out that "nvidia-settings" process was mentioned proc_ps.log in such proportion:
- 66 times for Unity 3D and
- 21 times for Unity 2D.

That lead me to conclusion that disabling "nvidia-settings" may improve boot performance.
So I did "sudo chmod a-x /usr/bin/nvidia-settings" and the next boot in Unity 3D took the same 37 seconds (0:37.76) as with Unity 2D.

For sure it is not the solution, but at least a direction to look.

Moreover this unfortunately has nothing to do with wake-up delay, so keep looking into it.

Anyway, hope this helps.

P.S. Make sure you know what are you doing while dealing with system files.

Add trusted certificates from Firefox to Citrix ICA client in Ubuntu

For some connections Citrix ICA client may display message saying:
You have hot chosen to trust "XXX server", the issuer of the server's security certificate.

Basically if you have Mozilla Firefox installed on your PC you may easily use its certificates for Citrix client as well.

Do do it just copy them over to ICA Client certificate folder:
sudo cp /usr/share/ca-certificates/mozilla/* /opt/Citrix/ICAClient/keystore/cacerts

Enable menu icons in Ubuntu 11.10 Oneiric Ocelot

Back in the day menu icons were essential part of system interface, then it was possible to enable/disable those icons in Ubuntu-tweak etc.
With 11.10 release we are in position when only dconf-tools tool may help us.
So first of all we need to install dconf-tools (it is not installed by default).

sudo apt-get install dconf-tools

And then open dconf-editor (start typing "dconf" in Unity dash)
In dconf editor go to org->gnome->desktop->interface and enable menus-have-icons.

Transform one multi-channel sound card into 2 virtual stereo ones

I love music!
I may say that the only period of time I don't listen to music is when I'm asleep.
And essentially while sitting at my desktop at work I cannot escape temptation to tune to Last.fm.

Another thing to mention is I cannot wear headphones for too long. Even my Sennheiser HD-555 which are "open-desing" ones and extremely comfortable. So I prefer to enjoy some sort of loudspeakers. And I do have them.

But sometimes I have to talk with colleagues through Skype. And well... it's not so nice to bother colleague/s sitting right next to me (in the same room) with these conversations... at the same time they're OK with my music.

So basically I needed to split audio output of Skype and all other applications.
The first idea was to get an extra PC (some old one from garbage) and use as a remote player. It's possible to install there MPD or some other stuff that has an ability to be controlled remotely through local network for example.

But it was not so elegant and basically I didn't manage to find "extra PC".

At this point I though what if I try to play with PulseAudio setting which is default audio server in Ubuntu for years now.

And so I did.

This wiki article covers everything I needed: https://wiki.archlinux.org/index.php/PulseAudio#Splitting_front.2Frear

Below is an extract from it.

Splitting front/rear

You may want connect speakers to front analog output and headphones to rear output. It would be usefull to split front/rear to separate sinks. Add to default.pa:

load-module module-remap-sink sink_name=speakers remix=no master=alsa_output.pci-0000_05_00.0.analog-surround-40 channels=2 master_channel_map=front-left,front-right channel_map=front-left,front-right

load-module module-remap-sink sink_name=headphones remix=no master=alsa_output.pci-0000_05_00.0.analog-surround-40 channels=2 master_channel_map=rear-left,rear-right   channel_map=front-left,front-right

(replace alsa_output.pci-0000_05_00.0.analog-surround-40 to your sound card name that you got from 'pacmd list-sinks')

After that you can switch player between speakers and headphones.

To restart PulseAudio execute: pulseaudio -k

This will kill PulseAudio server and then it will be restarted automatically with new settings applied.

The only thing that surprised me then - I couldn't find a way or tool to select desired virtual output for particular application.

And it turned out this tool is "PulseAudio Volume Control" (pavucontrol).

Here's a screenshot:

Unfortunately pavucontrol isn't installed by default in Ubuntu 11.10 so one needs to install it:
sudo apt-get install pavucontrol

Another issue is that application which uses direct access to ALSA won't appear in pavucontrol and so it's impossible to control which output they use.

But this is also could be solved quite simple:

In order for ALSA to use PulseAudio it needs a special /etc/asound.conf (system wide settings) (recommended) or ~/.asoundrc (settings on a per user basis):

File: /etc/asound.conf

pcm.pulse {
    type pulse
}
ctl.pulse {
    type pulse
}
pcm.!default {
    type pulse
}
ctl.!default {
    type pulse
}

If you omit the last two groups, Pulseaudio will not be used by default. You will then need to change the ALSA device to "pulse" in the applications that you use to make it work.

That's it. I finally got what I was looking for and it cost me an hour to google and experiment a bit.

Enable access to domain SMB shares from Nautilus (gvfd) in Ubuntu 11.10 Oneiric Ocelot

While running Ubuntu 10.10 on my main desktop I was able to access SMB shares within our Windows domain easily with no setup tweaks.

Recently I tried just released Ubuntu 11.10 and got stuck in situation when Nautilus asked me for credentials upon attempt to open "smb://share/folder", I entered my user name, domain name and password, but immediately on pressing "OK" button I got right the same window to enter password.

Next step I tried was "smbclient" run in terminal.

 $ smbclient -k //sp-filer/public  
 kerberos_get_default_realm_from_ccache: failed to get default principal  
 session setup failed: NT_STATUS_MORE_PROCESSING_REQUIRED  
 did you forget to run kinit?  

 $ smbclient //sp-filer/public  
 Enter abrodkin's password:  
 session setup failed: NT_STATUS_MORE_PROCESSING_REQUIRED  
 did you forget to run kinit?  

 $ kinit  
 The program 'kinit' can be found in the following packages:  
  * krb5-user  
  * heimdal-clients  
 Try: sudo apt-get install <selected package>  

So I installed "krb5-user" package which in turn has "krb5-config" as a dependency.
During "krb5-config" setup I entered our domain server address into prompt.

 $ kinit  
 Password for user@DOMAIN.SERVER.COM:  

And right after this I got both smbclient and Nautilus working like a charm.

Note: It's important to use ALL CAPITALS in domain realm name!

Fix "make xconfig" in buildroot-2011.08

Buildroot-2011.08 could use both Qt3 and Qt4 for configuration menu representation depending on Qt version installed on host system.

But if there're both of them (for example Linux kernel prior 2.6.38 uses Qt3 and Qt4 I use for application development) you'll get weird error on attempt to execute graphical configuration utility of buildroot in question:

 $ make xconfig  
 mkdir -p /home/_private/Downloads/buildroot-2011.08/output/build/buildroot-config/lxdialog  
 make CC="/usr/bin/gcc" HOSTCC="/usr/bin/gcc" obj=/home/_private/Downloads/buildroot-2011.08/output/build/buildroot-config -C package/config -f Makefile.br qconf  
 make[1]: Entering directory `/home/_private/Downloads/buildroot-2011.08/package/config'  
 /usr/bin/gcc -DCURSES_LOC="<ncurses.h>" -DLOCALE -I/home/_private/Downloads/buildroot-2011.08/output/build/buildroot-config -DQT_SHARED -DQT3_SUPPORT -I/usr/include/qt4 -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/Qt3Support -I/usr/include/qt4/QtNetwork -I/usr/include/qt4/QtSql  -D LKC_DIRECT_LINK -c qconf.cc -o /home/_private/Downloads/buildroot-2011.08/output/build/buildroot-config/qconf.o  
 In file included from qconf.cc:48:  
 /home/_private/Downloads/buildroot-2011.08/output/build/buildroot-config/qconf.moc:13: fatal error: private/qucomextra_p.h: No such file or directory  
 compilation terminated.  
 make[1]: *** [/home/_private/Downloads/buildroot-2011.08/output/build/buildroot-config/qconf.o] Error 1  
 make[1]: Leaving directory `/home/_private/Downloads/buildroot-2011.08/package/config'  
 make: *** [/home/_private/Downloads/buildroot-2011.08/output/build/buildroot-config/qconf] Error 2  

To fix this issue in Ubuntu you only need to set "moc" alternative to "moc-qt4", so /usr/bin/moc will point to "moc" from Qt4 instead of the one from Qt3 (which is set by default):

 sudo update-alternatives --config moc  
 There are 2 choices for the alternative moc (providing /usr/bin/moc).  
   
  Selection  Path       Priority  Status  
 ------------------------------------------------------------  
 * 0      /usr/bin/moc-qt3  45    auto mode  
  1      /usr/bin/moc-qt3  45    manual mode  
  2      /usr/bin/moc-qt4  40    manual mode  
   
 Press enter to keep the current choice[*], or type selection number: 2  

Fix black tooltip background in Eclipse

To solve black tooltip background in Eclipse in modern Ubuntu linux distributions ("Ambiance" theme):

Simply reset "System default" option and set preferred color of "Source hoover background" in "Preferences"->"C/C++"->"Editor"->"Appearance color options":

And here we go: