Archive for the 'Linux' Category


How-To disable IPv6 on RHEL6 / CentOS 6 / etc

Nov 25, 2014 in Linux


Proper way of disabling IPv6 subsytem in RedHat Linux 6 / CentOS 6 (dont unload modules or so)

in /etc/sysctl.conf : net.ipv6.conf.all.disable_ipv6 = 1

in /etc/sysconfig/network : NETWORKING_IPV6=no

in /etc/sysconfig/network-scripts/ifcfg-eth0 : IPV6INIT=”no”

disable iptables6 – chkconfig –level 345 ip6tables off


Bash comparison operators ..

Sep 21, 2011 in Linux

bash Comparison Operators ..

Some of them:

compound comparison

-a logical and

exp1 -a exp2 returns true if both exp1 and exp2 are true.

-o logical or 

exp1 -o exp2 returns true if either exp1 or exp2 is true.

.. and more ..

Entropy ..

Jul 22, 2011 in Algorithms, Linux


Entropy is the measure of the random numbers available from /dev/urandom, and if you run out, you can’t make SSL connections.

cygwin fstab mount

Apr 13, 2011 in Linux

add this to /etc/fstab

C: /c ntfs binary,posix=0,user


Extract rpm files ..

Feb 20, 2011 in Fedora, Linux, RedHat_EL

rpm2cpio myrpmfile.rpm | cpio -idmv


rpm verify package file ..

Oct 20, 2010 in Linux

rpm -K | –checksig file.rpm

How to clear linux memory cache ..

Aug 26, 2010 in Linux


$ sync; echo 3 > /proc/sys/vm/drop_caches

Wait for caches to be flushed..

$ sync; echo 0 > /proc/sys/vm/drop_caches

List contents of an rpm ..

Jul 30, 2010 in Fedora, Linux, RedHat_EL


To list the contents of the RPM techrx.rpm use this command:

rpm -qlp techrx.rpm

Find broken symlinks in Linux ..

Mar 24, 2010 in Linux

From ..

for lx in `find . -type l`
  if [ ! -e $lx ]
    echo $lx

Basic NIS / yp Client Configuration ..

Mar 22, 2010 in Linux, Network

NIS = Network Information Service, YP = Yellow Pages

1. Add domain to file /etc/sysconfig/network


2. Add IP to NIS server to /etc/yp.conf file

domain mydomain server

3. Start it

/etc/init.d/ypbind start