When many people think of the Cloud, they think that their application is running on a nebulous collection of resources that’s impervious to hardware failures. Despite a lot of the marketing material in the industry, this just isn’t the case. Beneath every Cloud there is hardware, and when that hardware fails, the results to some Clouds can be devastating.
When every server is an island
Many Clouds (like Rackspace’s) use local storage on each server in the Cloud. When a server in this kind of Cloud fails, your virtual machine goes down with it. Your VM can only be brought back online when the physical server is up and running again (or it’s restored from a backup). If you’re using Amazon’s EC2 Cloud without Elastic Block Storage, your VM’s data is gone forever if the physical server fails! In both cases, this can mean a whole lot of downtime for you and your application.
Enter Shared Storage
Thankfully, there’s a solution to this problem. The INetU Gated Community Cloud™ does things a bit differently. We store all of the data from your virtual machine on an enterprise-grade SAN that can be accessed by other physical servers in the Cloud. If the physical server that your VM is on fails, your VM is powered up on a different physical host in minutes. To your virtual machine and application, it simply looks like a reboot.
That begs the question—why isn’t everyone doing this? Before I answer that, I want to point out that many enterprises with internal Clouds do use a SAN to store their critical virtual machines. Like most good things, enterprise grade SANs don’t come cheap, and many Cloud providers decide to cut this corner in order to save a few dollars. Can your business afford to cut this corner? For a mission critical site or application, the answer is very often a resounding “No”!
