Posts Tagged ‘Ubuntu’
Debugging of ISPConfig 3 server actions in case of a failure
The follwing article describes the steps that can be taken to debug the ISPConfig 3 server scripts.
Enable the debug Loglevel in ISPConfig
Login to the ISPConfig intterface and set the log level to Debug under System > System > Server Config (see also chapter 4.9.2.2 of the ISPConfig 3 manual) for the affected server. After one or two minutes, there should be more detailed messages in ISPConfig’s system log (Monitor > System State (All Servers) > Show System-Log).
Disable the server.sh cronjob
Go to the command line of the server on which the error happens (on multiserver systems, it is often the slave and not the master) and run (as root):
crontab -e
Comment out the server.sh cron job:
#* * * * * /usr/local/ispconfig/server/server.sh > /dev/null >> /var/log/ispconfig/cron.log
Run the server script manually to get detailed debug output
Then run the command:
/usr/local/ispconfig/server/server.sh
This will display any errors directly on the command line which should help you to fix the error. If you have fixed
the error, please don’t forget to uncomment the server.sh cron job again.
Enable USB Support In Virtualbox (Ubuntu)
Enabling USB Support in Virtualbox means to be able to access USB drives plugged into your physical machine on your virtual machines. To accomplish this, you first need to download the newest version of Virtualbox (4.1.8 at the time of this writing), which is not available in the Ubuntu repositories but on the Virtualbox homepage:
https://www.virtualbox.org/wiki/Downloads
Uninstall any previously installed version if present and then install the downloaded Debian package with a package installer taking care of dependencies, such as gdebi.
Next, head back to the homepage and install the Virtualbox Extension pack which supports USB 2.0.
Now you have to make yourself member of the vboxusers group. Go to the Users and Groups Settings in your Control Panel and hit Manage Groups. Scroll down to the vboxusers group and hit Properties. Check the box next to your username and click OK.
Last but not least you have to enable USB for the virtual machine. Close it if it is running and enter the Settings window. On the left panel, select USB. Check Enable USB Controller as well as Enable USB 2.0 (EHCI) Controller. Then click the button with the small green plus-symbol and add the USB device you need:
If you run the machine a USB symbol will indicate that USB is enabled and a device is running on virtual machine:
Kill Processes On Ubuntu
When it comes to killing a frozen process, Ubuntu and its derivatives offer a great variety of ways to do so:
You can open the System Monitor to end or kill a running process. Just right-click and annihilate:
Then there is the Force Quit applet. Not that powerful, but does its job in most of the cases:
Working similarly but more powerful is the xkill command line tool. You can also wrap that one into a launcher and use it the same way as an applet.
Another command line tool is killall followed by the name of the process, granting the advantage of not having to know the process ID of the program, which the next tool requires:
kill, provided with the -9 switch and the ID of the process (available with top or ps) shuts down nearly every running process.
If none of those commands help, there is still the option to close the current session with ctrl + alt + backspace. This however comes with the warranty of losing any data you could not save before!
Install .deb Packages Manually (Linux Debian/Ubuntu)
When you download packages for Linux Debian or Ubuntu they usually come in the .deb format and are installed automatically by your local package manager. If you download them from the internet instead of the repositorial way however you are given the .deb file and have to deal with it yourself. To install it, open a terminal, direct it to the folder where it has been downloaded to with cd and use the dpkg command:
cd /home/ctest/Downloads/
dpkg -i random_name.deb
How to get detailed information about the harddisk installed on a Linux server
Detailed information about the hard disk type, disk vendor etc. of the disk used on a Linux system can be aquired with the linux tool hdparm. If hdparm is not installed on your server, it can be installed with this command (on Debian and Ubuntu systems):
apt-get install hdparm
For other Linux distributions, use the software installer and search for the package name ‘hdparm’.
To get the detailed disk info, run this command
hdparm -I /dev/sda
The device /dev/sda is the first SATA disk on the server, the second disk is /dev/sdb. Replace /dev/sda in the command with the name of the device that you want to query.
Get the disk health status with SMART monitor tools on Debian and Ubuntu Linux
Every modern disk has a internal monitoring function called SMART that keeps track on errors in that disk. There is a software package called smartmontools on Linux which can be used to query the SMART status of the disk to monitor if the disk might fail in near future.
Installation
apt-get install smartmontools
Usage
First we need to know the internal device name of the harddisks. For the first SATA disk, this is normally /dev/sda, the second is /dev/sdb etc. If you are unsure about the device names of your computer, then you can get them with:
fdisk -l
The command lists the partitions e.g. /dev/sda1. To get the device name, use the partition name without the number, e.g. the device of partition/dev/sda1 is /dev/sda.
To get a summary of the healt status of the disk, run:
smartctl –health /dev/sda
replace /dev/sda with the device name of the harddisk that you want to query.
The output will look similar to this:
~# smartctl --health /dev/sda smartctl version 5.38 [x86_64-unknown-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED
To get the full detailed output of all parameters, use this command:
smartctl –all /dev/sda
Install GNOME Desktop On Ubuntu 11.10
If you would like your Ubuntu 11.10 better with the old GNOME desktop (no launcher but a good old system panel and so on), you can just install the gnome package and choose it as your default desktop environment. Therefore open a terminal and enter:
sudo apt-get install gnome
During the installation there will be some prompts that you will have to answer. Click OK on the first one after you are done reading:
Next, you will have to decide which desktop environment you want to configure as your default:
After installation, the GNOME as well as the Unity desktops will be available on the cogwheel-button in the login-screen:
Encrypt Folders (Ubuntu Linux)
To encrypt folders on Linux Ubuntu there is a simple program called Cryptkeeper which, while active, lets you mount and dismount password protected folders.
While unmounted, the encrypted folders are invisible to the user. While mounted, you need to enter the password to access its contents. To create a new encrypted folder just click on the key icon on the system panel and select New encrypted folder.
Make sure to unmount the encrypted folders before you quit Cryptkeeper since the files become accessible if they are mounted and Cryptkeeper is inactive. The files remain invisible if they are unmounted and Cryptkeeper is quit.
Copy and Paste Multiple Entries (Ubuntu Linux)
To be able to copy and paste multiple entries with Control + C and Control + V there is an applet for the GNOME desktop panel called Glipper which is a clipboard manager and is available in the default Ubuntu repositories. If it does not show up in your list of applets after installation, restart your system and it should be available. Its menu is accessible over the panel icon and the key combination which is configured in the Preferences menu (Ctrl+Alt+C by default). The top entry is the one that will be pasted on Ctrl+V. To change it, just select another one.
In Preferences, you can also configure on what actions selections should be copied into the clipboard, if they should be remembered on system restart and how many entries should be remembered.
Quicklink Current Files on the Desktop Panel (Ubuntu Linux)
There is a desktop panel applet for Ubuntu Linux and its derivatives that is able to store files and folders within a dropdown window accessible from a tiny icon on the panel bar called Topshelf. It is available in the default Ubuntu repositories.
It receives content by just dragging and dropping it into its window which opens upon clicking the topshelf icon. This way you do not have to browse long ways through the file system to find the files you are working on regularly but have easy access on them by quicklinking.
