For one, you will need a dedicated server/VPS that supports SSH. Otherwise you won’t be able to do it.

Here’s exactly how I do it.

1) I go to my WordPress directory using the command cd. ~ 2 seconds

2) I use wget to pull the latest wordpress files, “wget http://wordpress.org/latest.tar.gz” ~ 3 seconds

3) Then I unzip the tar file using “tar xvf latest.tar.gz” ~ 5 seconds (see tar command howto here)

4) Then I remove the wp-admin and wp-includes directories by doing “rm wp-admin -rf” and “rm wp-includes -rf“. ~ 3 seconds

5) Next I will copy over the old WordPress files with the new ones using commands, “cp wordress/* . -rf –reply=yes” ~ 2 seconds.

6) I am done, that’s 2+3+5+3+2=15 seconds. If you are on at least a quad-core CPU server, downloading and unzipping should be rather fast but for those of you on slower servers, give it couple more seconds as download/unzip will take longer.

This is lightening fast compared to downloading WordPress files to your computer, unzipping it then uploading them to your website via FTP. And if you are on shared hosting, sometimes uploading FTP can take forever.

Even if you use built-in upgrade functions in WordPress, you are not going to beat SSH, not even a chance.

Of course, even better than this is to write a simple bash shell script that will do all the above for you. Then you could probably do it in just about 5 seconds. I will try to write a script soon and let you know on that btw. (I just realize it!)

Word of caution, this hack has worked fine for me for a new Twitter app site I am making that requires use of PHP 5.2 but if you have non-standard customizations to your server, you might want to test it first.

I’ve also found that JSON library that comes with PHP 5.2 is like 20 times faster rather than trying to run separate JSON libraries with PHP 5.1.6. It made a HUGE difference let me just say in page loading times. (Like .90 seconds versus 0.003 seconds.)

This guide describes how to upgrade the standard PHP 5.1.x packages in CentOS 5.x 32-bit to the current development versions 5.2.x. These instructions were created using CentOS 5.3 32-bit and with the following PHP packages installed:

# rpm -qa |grep php

php-common-5.1.6-15.el5.i386

php-cli-5.1.6-15.el5.i386

php-5.1.6-15.el5.i386

php-pdo-5.1.6-15.el5.i386

php-bcmath-5.1.6-15.el5.i386

php-ldap-5.1.6-15.el5.i386

php-devel-5.1.6-15.el5.i386

php-gd-5.1.6-15.el5.i386

php-xml-5.1.6-15.el5.i386

php-mbstring-5.1.6-15.el5.i386

php-mysql-5.1.6-15.el5.i386

php-dba-5.1.6-15.el5.i386

As long as you’re using the standard PHP packages on your CentOS server you won’t need to do anything extra. If you’re using extra PHP packages that aren’t part of the standard CentOS repositories (like php-mcrypt) you’ll have to remove them or find updated versions of them.

via cent.os