Memcache extension provides handy procedural and object oriented interface to memcached, highly effective caching daemon, which was especially designed to decrease database load in dynamic web applications. This article will explain how to install the memcache PHP extension on Centos/RedHat/Fedora.

The first, download the latest & stable package from http://pecl.php.net/package/memcache. Type the following command

# wget http://pecl.php.net/get/memcache-2.2.6.tgz

Extract memcache-2.2.6.tgz

# tar zxvf memcache-2.2.6.tgz

To install memcache extension, you need to install the php-devel package that matches the version of php that you are currently running. Example, i’m using PHP 5.3 then enter

# yum install php53-devel

Run the phpize command to prepare the build environment for a PHP extension

# phpize

Sample output

Configuring for:
PHP Api Version:         20090626
Zend Module Api No:      20090626
Zend Extension Api No:   220090626

Configure & Install memcache extension. Type the following command

# ./configure
# make
# make install

If your get the following error message when run ./configure

checking for the location of ZLIB... no
checking for the location of zlib... configure: error: memcache support requires ZLIB. Use --with-zlib-dir= to specify prefix where ZLIB include and library are located

Then type the following command to fix it

# yum install zlib zlib-devel

Finally, use the following command to add memcache extension to php.ini

# echo "extension=memcache.so" >> /etc/php.ini

The post How To Install Memcache PHP Extension appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.

Iptables should be installed by default on all CentOS 3.x, 4.x and 5.x installations. You can check to see if iptables is installed on your system by:

# rpm -q iptables

Sample output

iptables-1.3.5-5.3.el5_4.1

How to enable firewall

Login as root and type the following command

# /etc/init.d/iptables start
# chkconfig iptables on

If you are using IPv6, enter:

# /etc/init.d/ip6tables start
# chkconfig ip6tables on

And to see if iptables is actually running, we can check that the iptables modules are loaded, type the following command

# lsmod | grep ip_tables

Something look like:

ip_tables              29288  1 iptable_filter
x_tables               29192  6 ip6t_REJECT,ip6_tables,ipt_REJECT,xt_state,xt_tcpudp,ip_tables

How to disable firewall

Login as root and type the following command

# /etc/init.d/iptables stop
# chkconfig iptables off

If you are using IPv6, enter:

# /etc/init.d/ip6tables stop
# chkconfig ip6tables off

The post How To Enable/Disable Firewall On Centos / RedHat / Fedora appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.

chkconfig provides a  simple  command-line  tool  for  maintaining  the/etc/rc[0-6].d  directory  hierarchy by relieving system administrators of the task of directly manipulating the  numerous  symbolic  links  in those directories.

chkconfig has five distinct functions: adding new services for  management,  removing  services  from management, listing the current startup information for services, changing the  start-up  information  for  services, and checking the start-up state of a particular service.

Synopsis

chkconfig --list [name]
chkconfig --add name
chkconfig --del name
chkconfig [--level levels] name <on|off|reset>
chkconfig [--level levels] name

Example

List status for all services

chkconfig --list

List status for test service

chkconfig --list test

Add service called test

chkconfig --add test

Delete service called test

chkconfig --del test

Turn on & Turn off service

chkconfig --level 3 5 httpd off

The command above will turn off httpd service in run levels 3 and 5.

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