We know that Linux on servers is big and getting bigger. We also knew that Linux, thanks to open-source cloud programs like Eucalyptus and OpenStack, was growing fast on clouds. What he hadn’t know that Amazon’s Elastic Compute Cloud (EC2), had close to half-a-million servers already running on a Red Hat Linux variant.

Huang Liu, a Research Manager with Accenture Technology Lab with a Ph.D. in Electrical Engineering whose has done extensive work on cloud-computing, analyzed EC2’s infrastructure and found that Amazon EC2 is currently made up of 454,400 servers.

While Amazon has never officially said what it’s running as EC2’s base operating system, it’s generally accepted that it’s a customized version of Red Hat Enterprise Linux (RHEL). On top of that, for the virtual machines, Amazon uses the Xen hypervisor to host Linux; OpenSolaris; Solaris; Windows 2003 and 2008; and FreeBSD and NetBSD virtual machine instances.

Amazon also doesn’t talk about how many servers their popular cloud is made up of, so Huang had to work it out. He explained, “Figuring out EC2’s size is not trivial.

Amazon EC2 cloud is made up of almost half-a-million Linux servers. More >