Archive for the 'Linux' Category

 

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

Nov 25, 2014 in Linux

from: http://blog.acsystem.sk/linux/rhel-6-centos-6-disabling-ipv6-in-system

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

reboot

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 ..

http://tldp.org/LDP/abs/html/comparison-ops.html

Entropy ..

Jul 22, 2011 in Algorithms, Linux

From: http://rackerhacker.com/2007/07/01/check-available-entropy-in-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

from: http://www.cyberciti.biz/tips/how-to-extract-an-rpm-package-without-installing-it.html

rpm verify package file ..

Oct 20, 2010 in Linux

http://www.rpm.org/max-rpm/ch-rpm-checksig.html

rpm -K | –checksig file.rpm

How to clear linux memory cache ..

Aug 26, 2010 in Linux

From http://www.scottklarr.com/topic/134/linux-how-to-clear-the-cache-from-memory/

$ 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

From http://www.tech-recipes.com/rx/1419/list-files-in-an-rpm-package/

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 zulutips.com ..

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

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

NISDOMAIN=mydomain

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

domain mydomain server 192.168.2.25

3. Start it

/etc/init.d/ypbind start