Archive for the ‘Distributions’ Category
How to convert RPM software packages to Debian (.deb)
Maybe you had this problem already: you use Debian or Ubuntu Linux and a software package that you like to install is only available in RPM format. The solution is a handy tool called alien, which converts .rpm files to .deb. Installing alien:
apt-get install alien
Converting a rpm package to debian format:
alien --to-deb /tmp/mysoftwarefile.rpm
Conversions from .deb to rpm are also possible:
alien --to-rpm /tmp/mysoftwarefile.deb
How to Update ISPConfig 3
The ISPConfig update script is a easy way to update a ISPConfig 3 installation. If you want to backup the installation before, take a look at the instructions at the end of the article.
To update ISPConfig 3, login as root user on the shell of your server and run the command:
ispconfig_update.sh
>> Update
Please choose the update method. For production systems select 'stable'. The update from svn is only for development systems and may break your current setup.
Select update method (stable,svn) [stable]:
You should always select “stable” on a production system. The “svn” version is only suitable for ISPConfig 3 development.
The updater will then check the version of your system, download the latest update and starts the update process. In the next step, enter the mysql root password:
This application will update ISPConfig 3 on your server. MySQL root password []:
Then you were asked if the services shall be reconfigured:
Reconfigure Services? (yes,no) [yes]:
You should choose “yes” here, only if you modified your system configuration manually, it might be better to choose no. But in this case, new features in ISPConfig might not work or functions might stop working until you adjusted the config files manually. So its always a good choice to select ‘yes’ here. In the next step, select the ispconfig port:
ISPConfig Port [8080]:
Port 8080 is the default, if you have not changed it, press enter. Otherwise enter the port number and then press enter. As the last step, you wre asked if the crontab shall get reconfigured, you can select yes here by just pressing return.
Reconfigure Crontab? (yes,no) [yes]:
The ISPConfig updater will then update the ispconfig files and restart services, if the configuration has been changed.
Backup before updates
Before you update a software, it is always a good idea to backup all relevant data. This enables you to restore the software version that you had before in case of an error. The steps to create a backup of the ispconfig software and settings are:
Create a backup folder:
mkdir /home/backup chmod 700 /home/backup cd /home/backup
Backup the database
mysqldump -u root -p dbispconfig > dbispconfig.sql
Backup the ISPConfig software
tar pcfz ispconfig_software.tar.gz /usr/local/ispconfig
Backup the configuration files in /etc
tar pcfz etc.tar.gz /etc
This backup does not include the emails and website data.
Keep the spamassassin filter rules up to date in ISPConfig 3
To update the spamassassin rules regularily on your ISPConfig 3 server, add the following line to the root crontab by running:
crontab -e
then insert the following line:
23 4 */2 * * /usr/bin/sa-update --no-gpg &> /dev/null
and save the file. The path to the sa-update script is /usr/bin/sa-update on Ubuntu and Debian Linux, if you use a different linux distrubution, run the command:
which sa-update
to find the location of the sa-update script and adjust the path in the crontab line above so that it matches the path on your system.
How to use apt-file to find which .deb package contains a specific file
Sometimes you need to know which debian package contains a specific file e.g. because you deleted a system file accidently or you try to install a new software that requires this file. The apt package management utility which is used in Debian and Ubuntu comes with a handy tool called apt-file which allows a saerch for filenames in the package database.
Install apt-file
apt-get install apt-file
Update the apt-file database
apt-file update
Search for a specific file name, e.g. “lcrypto”
apt-file search /bin/bash
apt-file search /bin/bash bash: /bin/bash bash: /usr/bin/bashbug bash-minimal: /bin/bash-minimal bash-static: /bin/bash-static bashdb: /usr/bin/bashdb mybashburn: /usr/bin/bashburn
Make the gnome desktop in Ubuntu 9.10 to look like Windows XP
The following steps describe the Installation of the XPGnome theme for Ubuntu Linux. Run the following commands in the Ubuntu Shell window to make Ubuntu look like Windows XP:
cd /tmp wget http://ubuntu.online02.com/files/XP_Gnome.tar.gz cd XP_Gnome ./InstallXpGnome.sh
Screenshots:
http://ubuntu.online02.com/node/14
Optimize MySQL performance with mysqltuner
The following tutorial describes the steps to optimize the performance of a MySQL database with the mysqltuner script.
Login to your server on the shell, then execute the following commands:
Download the mysqltuner script:
cd /usr/local/bin wget http://mysqltuner.pl/mysqltuner.pl chmod +x mysqltuner.pl
Run mysqltuner
/usr/local/bin/mysqltuner.pl
Then enter root as username and the mysql root password.
You will get a output similar to this:
root@v221:/usr/local/bin# /usr/local/bin/mysqltuner.pl
>> MySQLTuner 1.0.1 - Major Hayden <major@mhtx.net> >> Bug reports, feature requests, and downloads at http://mysqltuner.com/ >> Run with '--help' for additional options and output filtering Please enter your MySQL administrative login: root Please enter your MySQL administrative password:
-------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.0.51a-24+lenny2 [!!] Switch to 64-bit OS - MySQL cannot currently use all of your RAM
-------- Storage Engine Statistics ------------------------------------------- [--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster [--] Data in MyISAM tables: 26M (Tables: 215) [!!] InnoDB is enabled but isn't being used [!!] Total fragmented tables: 33
-------- Performance Metrics ------------------------------------------------- [--] Up for: 96d 23h 3m 41s (10M q [1.239 qps], 686K conn, TX: 701M, RX: 1B) [--] Reads / Writes: 44% / 56% [--] Total buffers: 58.0M global + 2.6M per thread (100 max threads) [OK] Maximum possible memory usage: 320.5M (12% of installed RAM) [OK] Slow queries: 0% (20/10M) [OK] Highest usage of available connections: 33% (33/100) [OK] Key buffer size / total MyISAM indexes: 16.0M/8.5M [OK] Key buffer hit rate: 99.9% (57M cached / 30K reads) [OK] Query cache efficiency: 78.6% (5M cached / 6M selects) [!!] Query cache prunes per day: 483 [OK] Sorts requiring temporary tables: 0% (0 temp sorts / 408K sorts) [!!] Temporary tables created on disk: 36% (269K on disk / 745K total) [OK] Thread cache hit rate: 99% (427 created / 686K connections) [!!] Table cache hit rate: 2% (64 open / 3K opened) [OK] Open file limit used: 11% (120/1K) [OK] Table locks acquired immediately: 99% (3M immediate / 3M locks)
-------- Recommendations ----------------------------------------------------- General recommendations: Add skip-innodb to MySQL configuration to disable InnoDB Run OPTIMIZE TABLE to defragment tables for better performance Enable the slow query log to troubleshoot bad queries When making adjustments, make tmp_table_size/max_heap_table_size equal Reduce your SELECT DISTINCT queries without LIMIT clauses Increase table_cache gradually to avoid file descriptor limits Variables to adjust: query_cache_size (> 16M) tmp_table_size (> 32M) max_heap_table_size (> 16M) table_cache (> 64)
The script recommends to adjust or add the following variables in the mysql my.cnf file. The location of my.cnf is normally /etc/my.cnf or /etc/mysql/my.cnf depending on the Linux distribution that is installed on your server.
Open the my.cnf file:
vi /etc/mysql/my.cnf
and increase or set the variables in the [mysqld] section of the file. Mine looks now like this:
[mysqld] # # * Basic Settings # user = mysql pid-file = /var/run/mysqld/mysqld.pid socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp language = /usr/share/mysql/english skip-external-locking # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. bind-address = 127.0.0.1 # # * Fine Tuning # key_buffer = 16M max_allowed_packet = 16M thread_stack = 128K thread_cache_size = 8 # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #max_connections = 100 table_cache = 128 #thread_concurrency = 10 # # * Query Cache Configuration # query_cache_limit = 1M
query_cache_size = 32M tmp_table_sizee = 64M max_heap_table_sizee = 32M
Then save the file and restart mysql. After a few hours, rerun mysqltuner and check again if the values are fine now or if the have to be increased to a higher value.
How to renew the SSL certificate for dovecot on Ubuntu Linux
To create new SSL certificates for the dovecot pop3 and imap server on Ubuntu, follow these steps:
Make a backup copy of the old key and certificate file
sudo cp /etc/ssl/private/dovecot.key /etc/ssl/private/dovecot.key.old sudo cp /etc/ssl/certs/dovecot.pem /etc/ssl/certs/dovecot.pem.old Create the new key file <p class="command">openssl genrsa -out /etc/ssl/private/dovecot.key 1024
Create the new certificate file, valid for 2 years
Then restart dovecot
/etc/init.d/dovecot restart
Find the .deb package that contains a specific file on Ubuntu or Debian Linux
Sometimes you need to know to which debian or ubuntu package a specific file belongs, e.g. because you deleted a system file and want to reinstall it. There is a handy utility called apt-file which searches for a filename in all debian packages.
Installation
apt-get install apt-file
Usage example
search for the file /etc/sysctl.conf
apt-file search /etc/sysctl.conf
result:
apt-file search /etc/sysctl.conf
procps: /etc/sysctl.conf
mypc:~#
Now we see that the file is part of the debian / ubuntu package with the name “procps”.
How does Ubuntu’s screenshot tool Take Screenshot actually work?
The easiest way to make screenshots is to use Take Screenshot. You find it under Applications/Accessoires.
First change the delaytime for the screenshot from 0 to 1 or 2 seconds. This is the time you have to mark the chosen area. You should be fine with 1 second!
Then choose your screenshot option, e.g. Grab the current window. Klick on Take Screenshot and activate the window you need.
Take Screenshot closes. If all works well, a pop-up comes up to ask where to save the screenshot, which comes a s a .png.
For another screenshot you have to open the application again, so put it best in your panel.
The uncommon thing is that you have to run first Take screenshot and then choose an object, and not the other way round. That’s it!
How to install a professional image editing tool (KRITA) for Ubuntu 9.10
KRITA is a free image editing tool that ist pretty versatile and helps you not only to edit images, but also to use it for more artistic work on e.g. tablet PCs. It will surely remind you of Photoshop.
The easiest way to install KRITA is to download it over the Ubuntu Software Center. Do not take the complicated way to install it manually…
First go to Applications/Ubuntu Software Center:
Type in the searchfield KRITA and press Enter to mark KRITA for installation.
As KRITA appears, double click it, and then just klick on the Install button, start the installation and wait some seconds.
Now KRITA should appear checked as it has beeninstalled. That’s it!
