Installing Software RAID on Centos 5/6/7 via SSH 11

Considering number of dedicated server rentals that just gives JBOD, setting up your own software raid is quite handy. This tutorial goes over the very basic of how it’s done. All of this should be done under root. Let’s say you have 3 disks: sda, sdb & sdc. The OS is mounted on the sda, so ...

Sphinx Search & Invision Power Board

I just finished tweaking Sphinx (and bunch of other stuff) for a client and sphinx was being terrible with full indexing! So bad on the first time that it brought the site down for a good 15 minutes and maybe another half hour of crawling speeds on the first run. This client’s db is bigger than ...

Webservers & Caches

Webservers & Caches
I’m a graph-diagram-table person. And when someone asks how web servers and caches are mixed, I now have an image to give them!   Now we can visually see how web server interacts with a page cache in apache, nginx & varnish. And how user cache and opcache for PHP are separated by services like ...

Installing the latest PHP (5.4.23 / 5.5.7) on CentOS/RHEL 1

Method 1 – Remi Repo The Remi Repository (famillecollet.com) maintains the newest PHP for CentOS, RHEL, etc. And by newest, I mean newer than all other major repos. All you need to do is install PHP with Remi enabled. As of writing this article, Remi has 5.4.23 for CentOS, RHEL, etc. If you want even ...

Understanding IOWait 4

IOWait definition & properties IOWait (usually labeled %wa in top) is a sub-category of idle (%idle is usually expressed as all idle except defined subcategories), meaning the CPU is not doing anything. Therefore, as long as there is another process that the CPU could be processing, it will do so. Additionally, idle, user, system, iowait, ...