Listing the mac addresses of nic cards excluding null or loopback MACs i.e. 00:00:00:00:00:00
grep -H . /sys/class/net/*/address | awk ‘{split($0,array,”address:”);print array[2]}’ | grep -v ’00:00:00:00:00:00′
Since live systems are near to impossible to fsck when running (unless you can pull one side of the mirror then clone it to the other (very messy).
Become Root
sudo su –
or
su –
As root create file in root folder a file named forcefsck
touch /forcefsck
Restart the system.
shutdown -r now
/usr/local/nagios/libexec/check_ifstatus -H localhost
 
Can’t locate Net/SNMP.pm in @INC (@INC contains: /usr/local/nagios/libexec /usr/local/lib/perl5 /usr/local/share/perl5 /usr/lib/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib/perl5 /usr/share/perl5 .) at ./check_ifstatus line 38.
BEGIN failed–compilation aborted at ./check_ifstatus line 38.
Solution:
yum install perl-Net-SNMP
After testing a nagios configuration update ( including a new service or renaming some host etc..) before committing the changes and reloading / restarting the nagios service a good test is the following:
/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
(more…)
On one of my servers running CentOS 6 I had iptraf not displaying the boxes in dialogues correctly. It’s usually fixed by updating the session configuration on putty to translate to utf-8 but in this case that did not work.
While the system is a clone from another machine where it works well (puppet confirms) all I had to do is create an alias in my ./bashrc for iptraf to NCURSES_NO_UTF8_ACS=1 iptraf as such :
# .bashrc
# User specific aliases and functions
alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'
alias iftop='NCURSES_NO_UTF8_ACS=1 iftop'
alias iptraf='NCURSES_NO_UTF8_ACS=1 iptraf'
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi
As you can deduce the same issue and solution happened with iftop. 🙂
Oh the result :
Ejnoy 🙂
# yum install yum-priorities
# rpm -Uhv http://apt.sw.be/redhat/el5/en/i386/rpmforge/RPMS/rpmforge-release-0.3.6-1.el5.rf.i386.rpm
# rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm
Install the JPackage Project repository.
I happened to need mkpasswd command in CentOS 6.3 minimal:
While there is no package for the tool it can be found in expect command. So run as shown :
yum install expect
Exim is no longer available as a standard package, but as with most pieces of Linux software, it’s still only a few commands away. If you want to install Exim to use, or just to try, all you need do is:
Install the EPEL (Extra Packages for Enterprise Linux) repository:
wget http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-5.noarch.rpm rpm -i epel-release-6-5.noarch.rpm
Install the Exim package
yum install -y exim-mysql
Disable Postfix (the default MTA)
service postfix stop chkconfig postfix off
Set Exim as the default MTA
alternatives --config mta
And finally start Exim
chkconfig exim on service exim start
You should now be running Exim, and probably want to visit the official documentation site.
alias ipv6 off
by
options ipv6 disable=1
Alternative (which might be easier and works on any release with /etc/modprobe.d):
# touch /etc/modprobe.d/disable-ipv6.conf # echo "install ipv6 /bin/true" >> /etc/modprobe.d/disable-ipv6.conf
alias ipv6 off alias net-pf-10 off
With the 5.4 update symbol/ipv6 module dependency capabilities have been introduced; therefore, if IPv6 has been previously disabled as above an upgrade to the bonding driver in 5.4 will result in the bonding kernel module failing to load. For the module to load properly use instead:
# touch /etc/modprobe.d/disable-ipv6.conf # echo "options ipv6 disable=1" >> /etc/modprobe.d/disable-ipv6.conf
Upstream employee Daniel Walsh recommends not disabling the ipv6 module but adding the following to /etc/sysctl.conf:
net.ipv6.conf.all.disable_ipv6 = 1
In a short way this is what I do:
[root@toro.maranello.local ~]#echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf
While there I would turn off the IPV6Tables service as well
[root@toro.maranello.local ~]# service ip6tables save [root@toro.maranello.local ~]# service ip6tables stop [root@toro.maranello.local ~]# chkconfig ip6tables off
nJoy 😉
Just a note for my favorite :
add to the ~/.bash_profile
PS1="\[\033[35m\]\t\[\033[m\]-\[\033[36m\]\u\[\033[m\]@\[\033[32m\]\h:\[\033[33;1m\]\w\[\033[m\]\$ "
result :
