Tip: Fixing X201 monitor brightness dim on CentOS 7.x / GNOME 3.14.x

This one was driving me crazy...

With a recent update (can't pinpoint which because I have the nasty habit of updating often but only rebooting once in a blue moon) my Lenovo X201 monitor started dimming the brightness after something that felt like 30s without input from mouse or keyboard.

...sigh...

This smelled like GNOME gsettings and after mucking around I found how to deal with the issue:
$ gsettings set org.gnome.settings-daemon.plugins.power idle-brightness 300

Basically gsettings can used to set the key (I've choosen to change from the previous set 30 to 300 seconds) of a target schema (idle-brightness) within the org.gnome.setting-daemon.plugins.power schema directory.

For more on gsettings:

1. $ man gsettings
2. $ gsettings help

Now wasn't that cool or what?

...sigh...

Tip: Fixing "gnome-screenshot" (No such file or directory) on CentOS 6.3

While pressing Prnt Scrn to take a window screenshot I got awarded with "cool" Metacity message window stating the following:

1. There was an error running gnome-screenshot:Failed to execute child process "gnome-screenshot" (No such file or directory)

I'm running a fresh CentOS 6.3 system installed using the x86_64 Live CD which shortly after installing it noticed that it didn't came with Disk Usage Analyzer. Putting the error message and the missing application points the problem to the package that provides both gnome-utils.

To fix the problem and also install the other missing applications:
 

1. $ su
2. # yum install gnome-utils -y

And that's it!

HowTo: Install Dropbox using Repoforge on CentOS 6.2 / SL 6.2

Dropbox is a Web-based file hosting service that uses networked storage provided by Dropbox, Inc to enable users to store and share files and folders with others across the Internet using file synchronization.

The good folks that maintain the Repoforge (also know as RPMforge) repository have added packages for Dropbox.

What does this mean? No need for workaround for using Dropbox's Fedora repository on CentOS / SL / RHEL.

This post assumes that you already have a Dropbox account, if you don't get one here.

If you're running a 32 bits system:

1. $ su
2. # rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
3. # rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm
4. # yum install nautilus-dropbox

On the other hand, if you have a 64 bits install issue the following commands:

1. $ su
2. # rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
3. # rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm
4. # yum install nautilus-dropbox
5. # echo '-b /usr/libexec/dropbox/' >/etc/prelink.conf.d/dropbox.conf

Users of 64 bit systems are required an extra step otherwise Dropbox will fail after reboot because prelink 'optimises' executables during bootup, however Dropbox has issues with those optimizations.

As part of installing the rpm package you'll be forced to restart Nautilus, afterwards point to Applications -> Internet and launch the new Dropbox entry.

A series of Dropbox installation windows will guide you during the rest of the setup.

To wrap-up add the username(s) that will use Dropbox on /etc/sysconfig/dropbox. For example, if the users that will use Dropbox are john and jane:

1. # vim /etc/sysconfig/dropbox
2. DROPBOX_USERS=john,jane

Now be patient, in a matter of minutes you'll have a synchronized Dropbox folder :)

Tip: Disable Compiz hot corner

Did you ever reached for the window close and have Compiz display all open windows? Well to me it happened one time too many until I decided I wanted to disable that "feature".

The culprit is the Compiz's scale plugin and the initiate_edge option which initiates Compiz's Window Picker.

However there a couple of ways of disabling the hot corner or assigning another corner than the default top right corner:

1. Issue the appropriate gconftool-2 command
2. Install and run gconf-editor
3. Or install and use ccsm

As methods 2 and 3 imply installing further packages or even enabling a new repository (method 3), I'll explain how to use gconftool-2 to achieve our goal.

To disable the hot corner:

1. $ gconftool-2 --type string --set /apps/compiz/plugins/scale/allscreens/options/initiate_edge Disabled

If you like to hot corner "feature" and would like to move it to the top left corner:

1. $ gconftool-2 --type string --set /apps/compiz/plugins/scale/allscreens/options/initiate_edge TopLeft

To change the hot corner to the bottom left corner:

1. $ gconftool-2 --type string --set /apps/compiz/plugins/scale/allscreens/options/initiate_edge BottomLeft

You can also change the hot corner to the bottom right corner:

1. $ gconftool-2 --type string --set /apps/compiz/plugins/scale/allscreens/options/initiate_edge BottomRight

To re-enable the default hot corner to the top right corner:

1. $ gconftool-2 --type string --set /apps/compiz/plugins/scale/allscreens/options/initiate_edge TopRight

This procedure was executed under CentOS 6.2 thus being applicable to Scientific Linux and RHEL however it can also applied to other Unix-like distributions.

Tip: Fix "pa_stream_writable_size() failed: connection terminated" GNOME Totem error

One of these day I launched a Matroska (.mkv) video when all of a sudden Totem crashes with the following error:

 pa_stream_writable_size() failed: connection terminated  

This error popped-up on CentOS 6.2 however upon investigating the error on Google I came across bug reports on several distribution ranging from CentOS 6, SL 6, Fedora 11-14, Ubuntu 9.10-10.10, etc.

The solution consists of changing PulseAudio configuration and reloading it:

1. $ su
2. # echo "resample-method = trivial" >> /etc/pulse/daemon.conf
3. # exit
4. $ pulseaudio -k

References:
https://bugzilla.redhat.com/show_bug.cgi?id=566915
https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/496616
https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/644644
http://pulseaudio.org/ticket/759

HowTo: Install Dropbox on CentOS 6.2 / SL 6.2

Update 19/05/2012:
The Repoforge repository has added Dropbox packages to their repository. As such, please refer to HowTo: Install Dropbox using Repoforge on CentOS 6.2 / SL 6.2 for up to date and easier instructions.

Dropbox is a Web-based file hosting service that uses networked storage provided by Dropbox, Inc to enable users to store and share files and folders with others across the Internet using file synchronization.

Dropbox is available for a huge variety of operating systems, including Android, Linux, Windows, Mac OS X, among others, so in this HowTo I'll detail the steps required to have it running on RHEL6 clones such as CentOS 6.2 and Scientific Linux 6.2.

This post assumes that you already have a Dropbox account, if you don't get one here.

Though the good folks at Dropbox don't keep a repository for RHEL6 clones, the available repository files work perfectly on CentOS 6.2 and Scientific Linux 6.2.

For a 32-bit system download:

 $ wget -c https://www.dropbox.com/download?dl=packages/fedora/nautilus-dropbox-0.7.1-1.fedora.i386.rpm  

If running a 64-bit instead download:

 $ wget -c https://www.dropbox.com/download?dl=packages/fedora/nautilus-dropbox-0.7.1-1.fedora.x86_64.rpm  

Having downloaded the package it's time to install it:

# rpm -Uvh nautilus-dropbox-0.7.1-1.fedora.*.rpm  

As part of installing the rpm package you'll be forced to restart Nautilus, afterwards point to Applications -> Internet and launch the new Dropbox entry.

Now a series of Dropbox Installation windows will guide you during the rest of the setup. In a matter of minutes you'll have a synchronized Dropbox folder; in my case this means synchronizing 2 Windows systems, 2 Linux systems and 1 Android phone (I'm investigating on how to get it working on FreeBSD).

Fixing Dropbox YUM repository error:
As a side effect of installing Dropbox YUM repository whenever you try to use YUM you'll get the following error:

 http://linux.dropbox.com/fedora/6/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404"  
 Trying other mirror.  
 Error: Cannot retrieve repository metadata (repomd.xml) for repository: Dropbox. Please verify its path and try again  

The error originates from the fact that we're not using a RHEL6 repository but a Fedora 16 one. To fix the error edit the dropbox.repo file and replace baseurl=http://linux.dropbox.com/fedora/$releasever/ with baseurl=http://linux.dropbox.com/fedora/16/.

 # vim /etc/yum.repos.d/dropbox.repo  

 [Dropbox]  
 name=Dropbox Repository  
 #baseurl=http://linux.dropbox.com/fedora/$releasever/  
 baseurl=http://linux.dropbox.com/fedora/16/  
 gpgkey=http://linux.dropbox.com/fedora/rpm-public-key.asc  

It is advisable that you keep an eye out on Dropbox Linux page https://www.dropbox.com/install?os=lnx as the repository might change by the time of Fedora 17.

HowTo: Enable NTFS read and write access on CentOS 6.2 / SL 6.2

Whether we like it or not sooner or latter an USB key or an USB HDD formatted with NTFS filesystem will make acquaintances with our systems. With than in mind, this post aims to explain the steps needed to enable read and write capabilities to a CentOS 6.2 and SL 6.2 systems though the same steps should be applicable to latter versions of the RHEL clones.

To be able to mount and access NTFS filesystems on a CentOS 6.2 or SL 6.2 desktop, the fuse-ntfs-3g and gnome-vfs2-ntfs packages have to be downloaded and installed from either the RPMforge or EPEL repository.

For this how to I'll be using the RPMforge, so let's start by adding the repository:

On a 32-bit system:
$ su 
# rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt 
# rpm -Uvh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm  

On a 64-bit system:
$ su 
# rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt 
# rpm -Uvh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm 

After setting up the repository, proceed to install the required packages. It should be noted that ntfsprogs will also be installed as an dependency to gnome-vfs2-ntfs:
# yum install fuse-ntfs-3g gnome-vfs2-ntfs 
# hash 

fuse-ntfs-3g provides the opensource ntfs-3g driver that allows for full read-write access to NTFS, gnome-vfs2-ntfs allows GNOME VFS clients to use the NTFS library while ntfsprogs is a suite of NTFS utilities that includes ntsinfos (shows information on NTFS volumes), ntfslabel (show or sets NTFS volume labels) and nftsmount (mount read/write NTFS volumes) among others.

The NTFS volumes will appear in GNOME and double clicking them will mount them and make them browsable in Nautilus.

HowTo: Enable desktop effects on CentOS 6.2 / SL6.2

In previous versions of CentOS and Fedora the Desktop Effects menu under System -> Preferences allowed for the use of 3D desktop effects courtesy of compiz.

To enable the menu in CentOS 6.2 and SL 6.2 you'll need to install both compiz-gnome and desktop-effects packages assuming 3D drivers are installed.

compiz-gnome provides the compiz window manager and integration with the GNOME desktop environment while desktop-effects had a simple but useful menu to turn on/off the compiz effects.

1. $ su
2. # yum install desktop-effects compiz-gnome

Now simply point to System -> Preferences -> Desktop Effects and enable the Compiz option. I personally like to also enable the Windows Wobble when Moved option ;)

Fix: Touchpad not working on OpenSUSE 11.0

All of a sudden the touchpad on my Dell D620 stopped working. After googling for an answer I came across a post on LinuxQuestions.org pointing to the solution.

To sum up, browse to Control Center > Sessions and deselect Touchpad from the Startup Programs tab. After restarting your session you'll be able to use the touchpad once again.

Note that the KDE desktop enviornment on OpenSUSE is unaffected by this bug, it only affects GNOME.

Props to LinuxQuestion.org user swampdog20002 having posed the question and posting updates on how he was solving the problem. That's the opensource spirit!