Exim4 does not transfer mails to the root user by default. If you’re trying to test Exim4 by sending an email to the root user, it will never be delivered to root user.That’s a default configuration from Debian. Instead, all emails for root user are transferred to /var/mail/mail.
Here is where it is configured :
root@localhost:~# cat /etc/exim4/conf.d/router/mmm_mail4root
# deliver mail addressed to root to /var/mail/mail as user mail:mail
# if it was not redirected in /etc/aliases or by other means
# Exim cannot deliver as root since 4.24 (FIXED_NEVER_USERS)
debug_print = “R: mail4root for $local_part@$domain”
driver = redirect
domains = +local_domains
data = /var/mail/mail
file_transport = address_file
local_parts = root
user = mail
group = mail
If you need to redirect emails to root, then add the right user in /etc/aliases at line where root word stands. Then run the command newaliases to take this change into account. Send a test email to root and log in to the user you’ve just configured and check its email box with the mail command. You should be able to read the email you’ve just sent a few seconds before.
Some web-based management tools use Java applets to perform configuration tasks. Within Debian Squeeze, you have two JRE available : openjdk-6-jre and sun-java6-jre. Concerning web browsers, two kinds of Java plug-ins can be installed : the official Oracle Java plug-in from the sun-java6-plugin package and the alternative Icedtea plug-in from the icedtea6-plugin package.
The Oracle Java Plug-in is better suited for its integration within web browsers. To install it :
root@localhost:~#apt-get install sun-java6-plugin
To use one implementation of Java (either OpenJDK or Oracle java), make sure that your environment is properly configured. update-java-alternatives (utility from the java-common package) can be used for this purpose.
To list the existing Java environments :
root@localhost:~# update-java-alternatives -l
java-6-openjdk 1061 /usr/lib/jvm/java-6-openjdk
java-6-sun 63 /usr/lib/jvm/java-6-sun
To force the use of one given environment :
root@localhost:~#update-java-alternatives -s java-6-sun
To make sure that your installed applications only use the Oracle Java 6, check the output of update-alternatives -l . You should have the following output :
root@localhost:~#update-alternatives -l |grep java
update-alternatives –get-selections |grep java
appletviewer manual /usr/lib/jvm/java-6-sun/bin/appletviewer
apt manual /usr/lib/jvm/java-6-sun/bin/apt
ControlPanel manual /usr/lib/jvm/java-6-sun/jre/bin/ControlPanel
extcheck manual /usr/lib/jvm/java-6-sun/bin/extcheck
firefox-javaplugin.so manual /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
HtmlConverter manual /usr/lib/jvm/java-6-sun/bin/HtmlConverter
iceape-javaplugin.so manual /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
iceweasel-javaplugin.so manual /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
idlj manual /usr/lib/jvm/java-6-sun/bin/idlj
jar manual /usr/lib/jvm/java-6-sun/bin/jar
jarsigner manual /usr/lib/jvm/java-6-sun/bin/jarsigner
java manual /usr/lib/jvm/java-6-sun/jre/bin/java
javac manual /usr/lib/jvm/java-6-sun/bin/javac
javadoc manual /usr/lib/jvm/java-6-sun/bin/javadoc
javah manual /usr/lib/jvm/java-6-sun/bin/javah
javap manual /usr/lib/jvm/java-6-sun/bin/javap
java_vm manual /usr/lib/jvm/java-6-sun/jre/bin/java_vm
javaws manual /usr/lib/jvm/java-6-sun/jre/bin/javaws
jconsole manual /usr/lib/jvm/java-6-sun/bin/jconsole
jcontrol manual /usr/lib/jvm/java-6-sun/jre/bin/jcontrol
jdb manual /usr/lib/jvm/java-6-sun/bin/jdb
jexec manual /usr/lib/jvm/java-6-sun/jre/lib/jexec
jhat manual /usr/lib/jvm/java-6-sun/bin/jhat
jinfo manual /usr/lib/jvm/java-6-sun/bin/jinfo
jmap manual /usr/lib/jvm/java-6-sun/bin/jmap
jps manual /usr/lib/jvm/java-6-sun/bin/jps
jrunscript manual /usr/lib/jvm/java-6-sun/bin/jrunscript
jsadebugd manual /usr/lib/jvm/java-6-sun/bin/jsadebugd
jstack manual /usr/lib/jvm/java-6-sun/bin/jstack
jstat manual /usr/lib/jvm/java-6-sun/bin/jstat
jstatd manual /usr/lib/jvm/java-6-sun/bin/jstatd
keytool manual /usr/lib/jvm/java-6-sun/jre/bin/keytool
midbrowser-javaplugin.so manual /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
mozilla-javaplugin.so manual /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
native2ascii manual /usr/lib/jvm/java-6-sun/bin/native2ascii
orbd manual /usr/lib/jvm/java-6-sun/jre/bin/orbd
pack200 manual /usr/lib/jvm/java-6-sun/jre/bin/pack200
pluginappletviewer auto /usr/lib/jvm/java-6-openjdk/jre/bin/pluginappletviewer
policytool manual /usr/lib/jvm/java-6-sun/jre/bin/policytool
rmic manual /usr/lib/jvm/java-6-sun/bin/rmic
rmid manual /usr/lib/jvm/java-6-sun/jre/bin/rmid
rmiregistry manual /usr/lib/jvm/java-6-sun/jre/bin/rmiregistry
schemagen manual /usr/lib/jvm/java-6-sun/bin/schemagen
serialver manual /usr/lib/jvm/java-6-sun/bin/serialver
servertool manual /usr/lib/jvm/java-6-sun/jre/bin/servertool
tnameserv manual /usr/lib/jvm/java-6-sun/jre/bin/tnameserv
unpack200 manual /usr/lib/jvm/java-6-sun/jre/bin/unpack200
wsgen manual /usr/lib/jvm/java-6-sun/bin/wsgen
wsimport manual /usr/lib/jvm/java-6-sun/bin/wsimport
xjc manual /usr/lib/jvm/java-6-sun/bin/xjc
xulrunner-1.9-javaplugin.so manual /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
xulrunner-javaplugin.so manual /usr/lib/jvm/java-6-sun/jre/lib/amd64/libnpjp2.so
For Iceweasel,you can check that your Java plug-in is configured by typing about:plugins in the address bar.
Perl is famous for its tremendous number of modules ready to use. They can be fetched and installed from the Comprehensive Perl Archive Network (CPAN)
One of the best way to add new modules into your system is to use the program cpan.
Before any manual installation, make sure that these modules are not packaged by Debian. According to the Debian Perl Policy , the Perl modules provided by Debian are located in the following folders :
For the core modules : (provided by perl-base and perl-modules packages)
For Debian packed modules :
Concerning the modules installed with cpan command :
If your host OS is Windows with a Linux flavor as a guest OS, here is a quick reminder of the steps to proceed to install or update the current VirtualBox guest additions.
The VirtualBox guest additions are located in the VBoxGuestAdditions ISO image which can be found in C:\Program Files\Oracle\VirtualBox
To install them, load this ISO image into your virtual CD/DVD drive and your OS guest should make it available through a mount point. Make a local copy of its content into a folder and launch the following command as root :
Verifying archive integrity… All good.
Uncompressing VirtualBox 4.1.22 Guest Additions for Linux………
VirtualBox Guest Additions installer
Removing installed version 4.1.16 of VirtualBox Guest Additions…
Removing existing VirtualBox DKMS kernel modules …done.
Removing existing VirtualBox non-DKMS kernel modules …done.
Building the VirtualBox Guest Additions kernel modules …done.
Doing non-kernel setup of the Guest Additions …done.
You should restart your guest to make sure the new modules are actually used
Installing the Window System drivers
Installing X.Org Server 1.7 modules …done.
Setting up the Window System to use the Guest Additions …done.
You may need to restart the hal service and the Window System (or just restart
the guest system) to enable the Guest Additions.
Installing graphics libraries and desktop services components …done.
Three services should be present in /etc/init.d :
After the install/upgrade of VirtualBox guest additions, reboot your guest OS to make the upgrade take effect.
For more information : Installing VirtualBox guest additions
If you have this error “CHECK_NRPE: Error – Could not complete SSL handshake” while configuring Nagios or Centreon, make sure that your (Nagios|Centreon) poller IP address is allowed in the remote monitored nrpe server configuration file. Just add the IP address :
Debian : cat /etc/nagios/nrpe.cfg
then, reload the nrpe server configuration file :
RedHat : cat /etc/nagios/nrpe.cfg
Then, restart the nrpe server configuration file (no option for reloading) :
root@localhost:~#service nrpe restart
If you have a slow SSH connection to a server with the following message :
debug1: An invalid name was supplied
Cannot determine realm for numeric host address
Make sure that the server you try to reach has a well-configured reverse DNS. Then, you can desactivate GSSAPI authentication by adding the following line to your ssh client configuration file :
fool@localhost:~$echo “GSSAPIAuthentication no” >> $HOME/.ssh/config
You should be able to connect to your server through SSH quicker.
With the recent upgrade of pulseaudio to version 1.1-3, you will probably encounter error messages while playing an audio file as the ones below :
[AO_ALSA] alsa-lib: conf.c:1220:(parse_def) show is not a compound
[AO_ALSA] alsa-lib: conf.c:1686:(snd_config_load1) _toplevel_:24:26:Unexpected char
[AO_ALSA] alsa-lib: conf.c:3406:(config_file_open) /usr/share/alsa/pulse-alsa.conf may be old or corrupted: consider to remove or fix it
I had the messages above with mplayer while listening to an on-line radio.
After searches, this has been recently filed as a bug : Debian bug 661095
Look at the following configuration file : /usr/share/alsa/pulse-alsa.conf
Make a copy of it before doing any changes :
root@localhost:~# cp /usr/share/alsa/pulse-alsa.conf /usr/share/alsa/pulse-alsa.conf.save
With your favorite text editor, remove all the lines starting at line 20 until the last line. Here is what you should have at last :
root@localhost:~# cat /usr/share/alsa/pulse-alsa.conf
# This file is referred to by /usr/share/alsa/pulse.conf to set pulseaudio as
# the default output plugin for applications using alsa when PulseAudio is
description “Playback/recording through the PulseAudio sound server”
You can now play any audio file with no more error messages.
Hope this help !
This message can occur while listening to a webradio with mplayer. Here is a more detailed message :
Requested audio codec family [mpg123] (afm=mpg123) not available.
Enable it at compilation.
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 44100 Hz, 2 ch, floatle, 96.0 kbit/3.40% (ratio: 12000->352800)
Selected audio codec: [ffmp3float] afm: ffmpeg (FFmpeg MPEG layer-3 audio)
To use this codec without compiling mplayer again, install the following Debian package :
root@localhost:~#apt-get install libmpg123-0
Then, enable the use of this codec within your own mplayer configuration file :
fool@localhost:~$echo “afm=mp3lib” >> ~/.mplayer/config
This option will force mplayer to use mpg123 codec instead of ffmp3float.
More information on mpg123 by Thomas Orgis from the official mpg123 website :
You need libmpg123 for the mpg123 codec in MPlayer, but the mp3lib codec is an internal fork of mpg123 code that fully resides in MPlayer.
So, if you want to use mp3lib, you can just say that in your ~/.mplayer/config … if you want mpg123, you need the lib and also MPlayer must be built with the codec enabled. Note that mp3lib will vanish sometime in favour of mpg123 usage (or ffmp3float, but I naturally hope the former;-), after some quirks have been settled.”