On an appliance I reinstalled with pfSense I was facing a problem booting the system from an usb stick.
The system was not able to mount the partition correctly because it wasn’t present at that time. For me this looks like a timing Problem. The system booted without a problem if I didn’t connect the USB stick directly. I used an USB-hub while installation and booting from that USB stick while it was connected through this hub worked like a charm.
My Problem was similar to this. https://redmine.pfsense.org/issues/495
The fix was quite easy. I booted the system using the USB-hub and modified the loader.conf
I just had to add this at the end of the file:
and everything worked fine even if I connected the USB stick directly to the appliance.
Hope this helps you if you’re facing a similar problem.
Last week I read some posts about Mozillas thoughts to sell space for advertisement in their Firefox Browser. Of course I don’t like advertisements in the web. And of course I don’t like apps with a lot of advertisement and much more I don’t like to be tracked on every webpage I go to but Mozilla is offering a service and a product I never paid something for.
There are not many companies left who fight for open solutions and systems. And more a shame is that those who are doing it, are often blamed for making money. Please stop this give me everything for free mentality only because you can look into the source code!
Mozilla makes a good job and the organization needs a lot of money. Beside this it is not healthy to get the biggest amount of money from Google. Oh and Google makes most of their money out of their advertisement business.
Due to a known bug in Fedora 20 with some selinux updates I recognized a connected problem on my machine. While updating some packages I found this message:
Security: kernel-3.12.8-300.fc20.x86_64 is an installed security update
Security: kernel-3.12.7-300.fc20.x86_64 is the currently running version
To fix this and get the latest kernel visible in grub and set as default I needed to reinstall it by running:
yum remove kernel-3.12.8-300.fc20
again. After this procedure the new kernel was available.
To fix the “couldn’t find IGL” error you probably get after installing Qt 5.2 package on Fedora 20 and you try to compile the first project, you should install the missing mesa package by running the following install command as root or using sudo:
sudo yum install mesa-libGL-devel -y
This should fix it.
Since I am using Fedora 20 now for a while on two machines I came over some smaller bugs with my configuration.
I installed my systems using the KDE spin and installed with en_US language but a german keyboard layout. It looks like something after installation on my workstation did go wrong with local generation. Because I reinstalled the workstation for testing some different configurations with UEFI, I am quite sure this error is reproducible for me.
This is what I recognized first when I opened a shell and tried to use sudo I got messages like this one:
-bash: warning: setlocale: LC_CTYPE: cannot change locale (en_US.UTF-8): No such file or directory
-bash: warning: setlocale: LC_COLLATE: cannot change locale (en_US.UTF-8): No such file or directory
-bash: warning: setlocale: LC_MESSAGES: cannot change locale (en_US.UTF-8): No such file or directory
-bash: warning: setlocale: LC_NUMERIC: cannot change locale (en_US.UTF-8): No such file or directory
-bash: warning: setlocale: LC_TIME: cannot change locale (en_US.UTF-8): No such file or director
First I didn’t give it a lot of attention because the shell worked fine and I thought I need just to export my correct LC_ALL variable. But then I got problems running libvirtd service on that machine. It was a fresh installed Fedora 20 and the libvirtd service didn’t want to start and quite while initialization. After some searching I found that this two problems are related.
I am not sure what did go wrong while installation or post installation process but because it is not a common known problem I think it is related to my configuration regarding language and keyboard layout. But I have to investigate some more to report a more qualified bug report than the usual bullsh** I fire them on their bug tool in general.
To fix the problem you need to generate the missing local files. This is done with different tools on most distributions. Arch, Gentoo and Ubuntu mostly refer to the locale-gen script which is not present on a default Fedora installation.
To regenerate your locale on Fedora run this command to fix the problem:
localedef -v -c -i en_US -f UTF-8 en_US.UTF-8
Of course you need to modify it to your local you want to have or which is missing on your system.
Since the Fedora 20 release called Heisenbug is now some weeks old and the first updates are available I decided to update my Thinkpad. As described in older posts I prefer to reinstall the system partition and only keep my /home partition which contains all my stuff.
This time I decided to migrate away from the default GNOME based spin of Fedora to the KDE based. Over the time they made a good job in screwing all this small GNOME stuff up and since I started a QT based project some weeks ago I need to install the QT dependencies anyway. But for my all day work I will still stick with the small i3wm tiling window manger just because I like the keyboard based window alignment.
The reinstallation works fine, I used the custom partitioning and reformated only my /boot and / partition. The disk is encrypted and it worked as expected with Luks through the complete reinstallation process. Of course you have to enter your pass phrase before you’re able to edit the encrypted partitions and mark them for reformating if you want to do so. For the data or home partition just set the mount point and of course don’t mark it for reformating if you want to keep your data. I usually keep only my data partition but this hardly depends on your setup. Keep in mind that for example the default directory for virtual machines is located in /var and this is by default part of your system partition if you don’t have a custom partitioning layout. You should review your existing configuration and files and have a complete backup before you start with such an update.
My i3wm configuration needs some modifications now because I used some gnome components in the past to manage sound and brigthness buttons on my thinkpad. I will provide some documentation for those who might also want to replace this gnome based stuff with smaller tools or tools which are incluced in the KDE spin by default.
There is a known bug with the kwallet component which should provide the safed password at login time for you wifi. It looks like the order for the component start leads to a annoying second password input window at login time in KDE but they are working on it to fix it. For some more information have a look here, on the time I wrote this the fix is on its way: https://bugzilla.redhat.com/show_bug.cgi?id=1043195
The Fedora 20 release for me looks quite good up to now. I installed it on two of my machines. The Thinkpad works without bigger problems and only needs my custom configurations applied as usual while on my new workstation there is a small problem with the initialization with some of my USB ports at boot time. Devices connected to this ports need to be reconnect after boot. I had no time to investigate deeper but opened a (lousy described) bug (https://bugzilla.redhat.com/show_bug.cgi?id=1046971) , maybe someone else is facing this problem on an ASUS Z87 Pro Board, too. Up to this both systems work very nice. Because my Thinkpad has an old dual graphics solution with an integrated Intel and an dedicated AMD HD 4200 card there where some problems with each distribution in the past. I decided to disable the AMD graphics in the Bios because I don’t need it and the system works more stable. Some problems which still appears with Fedora 20 and the enabled switcheroo stuff are disabled displays or brightness levels or high energy consumption if the AMD graphics is enabled. For example my display got disabled after I logged in into KDE. It was enabled the complete boot process but after the powersafe daemon in KDE started the screen was black and the brightness level on my console was on minimal level. I didn’t figured out how to reset this but had no time to investigate anyway this problem is gone with disabling the switchable graphic configuration in Bios.
With the Fedora 20 release some old tools are not installed by default anymore. The systemd daemon is more widely used and this brings some changes to the system you should be aware of since this changes will be included in the complete Linux landscape over the time. Because I use CentOS and RedHat Enterprise Linux for many production servers I will write a more detailed blog post to show the different within the system.
Useful configurations, tools and more for the Raspberry Pi
Finally found some time to write down some of my first experiences with my Raspberry Pi. I own some of this devices to play with them and use them for home server and run them with Linux to make things easier in my daily work. One of this Rasberry Pis is used to display the Zabbix monitoring and alarm page on a wall mounted TV. A second one is used to sync backups over a VPN to an encrypted USB disc to have an emergency backup on a second location. To get started with this devices you find a lot of tutorials on the internet and the distributions and software for this wonderful hardware is well documented. This may help you to do the first steps and find some links. I will update and add some sections from time to time to this post to share what worked for me.
After setting up the SDcard with Archlinux Image for Raspberry Pi I started to setup my favoured environment. Follow this instruction on the Archlinux website.
First update all installed software:
This should be done if you plan to run your Raspberry Pi as a home server or available over the Internet. Reboot thte system to be sure the last kernel is running.
Install some useful system tools:
pacman -S htop vim wget
SSH key authentication and X11 forwarding:
Per default the X11 forwarding is disabled and Password Authentication is enabled /etc/ssh/sshd_config. Because I want to test the X11 tools I installed on the PI for my Zabbix monitoring monitor, I had to enable this feature. I don’t use password authentication and disable it on my systems.
Enable X11 forwarding:
Disabling password authentication:
Modify HDMI output to fit to monitor
My Raspberry Pi is used with a Phillips television to show the Zabbix monitoring webpage for my servers. The pi is connected directly with HDMI to the monitor. The default configuration does not use the HD ready resolution which is 1080i if I am not wrong. To fix this I had to modify the /boot/config.txt file to set the video resolution. A good overview over all configuration variables is available here. For me hdmi_mode=5 1080i 60Hz works to use a better resolution but the screen still did not fit completely. To fix this I had to play with the overscan_top and overscan_bottom values. I had to choose quite high values like 25 and 30 for the variables to make the screen fit correctly and show the complete information but at the end it fixed the cut up picture.
Some weeks ago I finally reinstalled my Lenovo T-500 with Fedora 19 since Fedora 17 is end of life now. For Fedora 17 I built my own version of some packages like the i3wm tailing window manager. Fedora 18 and the new Fedora 19 include an actual i3wm with cairo support enabled. Some days ago a new version 4.6 of i3wm was released, I will backport this version for Fedora 19 within the next two weeks and add it to my yum repository.
For all users of my Fedora 17 yum repository I would advice you to update to Fedora 19 or at least Fedora 18, too.
On my T-500 I was facing a problem with the switcheroo configuration. I disabled the ATI graphic card by blacklisting the radeon kernel module. For me it looked like the order in which the graphic card was enabled at boot time was not persistent. This did lead to problems with the splash screen and X. I planed to write down how I disabled the module permanently to have it documented for other users, if you need the information now, send me an email.
Btw. I did not upgrade my system, I did an reinstall and reused my home partition. This is the most easy way for me to keep up to date with Fedora while keeping my data. I try to store everything important in my home directory and make a backup of all deeper system changes. Since there was no need to upgrade to Fedora18 this was even the only way to jump to Fedora 19 without hassle.
The new version works now a few weeks and got its first updates and kernel updates. After fixing the problem with my graphic cards the system works very stable. I am using the Gnome flavor but instead of gnome I am using i3wm as my favorite window manager. Some of the older gnome tools changed and because of this I am no longer able to use them to control for example the function keys. I did not investigate to fix this problem. It looks like the way Gnome controls ACPI, function keys and some more power saving functions changed in a bigger way. Since I am not really interested in reverse engineer this by my self I will wait for some posts from other Fedora i3wm users how to do this stuff.
Here is a very good post for all Fedora i3wm users: http://blog.seventhmoon.info/blog/2013/07/05/schrodingers-i3wm/
What is MQTT?
MQTT is the short name for MQ Telemetry Transport. It is a TCP based protocol which implements the publish and subscribe pattern. While the pubish and subscribe method became popular these days for mobile devices MQTT is one of the protocols becoming more and more popular. Actually MQTT is becoming an OASIS standard for the Internet of Things within the next few months.
Some more information are available here:
What is HiveMQ
HiveMQ is a MQTT broker which basically is the server part of MQTT. All messages in a MQTT communication are handled by a broker, it is the key component for this type of communication. HiveMQ is a Java based broker software with some extended functionality like building clusters and the possibility to easily extend the functionality with plugins. It is free for personal non-commercial use up to 25 concurrent connected clients. Check out the HiveMQ Website for all its features and documentation.
Java VM (OpenJDK 1.7)
SELinux should be off if you don't need it.
Allow incomming connections to TCP port 1883
Install OpenJDK 1.7
yum install java-1.7.0-openjdk.x86_64
Download, extract and run HiveMQ
wget --content-disposition http://www.hivemq.com/downloads/releases/latest
chmod 755 start.sh
The output should look something like this:
_ _ _ __ __ ____
| | | |(_) | \/ | / __ \
| |__| | _ __ __ ___ | \ / || | | |
| __ || |\ \ / // _ \| |\/| || | | |
| | | || | \ V /| __/| | | || |__| |
|_| |_||_| \_/ \___||_| |_| \___\_\
HiveMQ Start Script for Linux/Unix v1
Checking if Java is installed
Java was found. Starting HiveMQ....
No HIVEMQ_HOME is set, using default
Searching for HiveMQ in /hivemq-1.3.0....
2013-06-18 22:35:29,874 INFO - HiveMQ home directory: /hivemq-1.3.0
2013-06-18 22:35:29,879 INFO - Starting HiveMQ Server
2013-06-18 22:35:33,509 INFO - Activating statistics callbacks with an interval of 60 seconds
2013-06-18 22:35:33,510 INFO - Activating $SYS topics with an interval of 60 seconds
2013-06-18 22:35:33,812 WARN - No license file found. Using free personal licensing with restrictions to 25 connections.
2013-06-18 22:35:34,483 INFO - Starting on address 0.0.0.0 and port 1883
2013-06-18 22:35:34,514 INFO - Loaded Plugin Access Log Plugin - v1.0-SNAPSHOT
2013-06-18 22:35:34,516 INFO - Started HiveMQ in 4646ms
And that’s it! Try to connect your client to your ip on port 1883 and have fun. If you want to use a plugin, just extract it into your plugin folder and restart HiveMQ.
The new version 4.5 of i3 and i3status 2.7 is available for Fedora 17 over my repository. Short how to update i3wm on Fedora17 can be found here.
The detailed release notes are available here: http://i3wm.org/downloads/RELEASE-NOTES-4.5.txt
If your using Fedora 18 there should be some updated packages available in the main repositories.