Why not use a cloud storage provider?
The most persuasive argument against using cloud storage for primary storage is application performance. Application performance is highly sensitive to storage response times. The longer it takes for the application's storage to respond to a read or write request, the slower that application performs. Slow application performance leads to significant drops in employee productivity.
Many years ago, IBM Corp. did a study on user productivity. The report, "The Economic Value of Rapid Response Time," measured user productivity as application response time increased or decreased. What was discovered is that people notice a difference in application response times as little as 0.5 seconds. This report found that user productivity increased dramatically when application response time decreased from three seconds to 0.3 seconds.
Public cloud storage by definition resides in a location geographically distant from your physical storage when measured in cable distance. Response time for an application is measured in round-trip time (RTT), or the amount of time it takes for a read or write request to get to the cloud storage and back to the application. There are numerous factors that add to that RTT. One is speed of light latency, which there is no getting around today. Another is TCP/IP (standard protocol for the Internet) latency. Then there is a little thing called packet loss that can really gum up response time because of retransmissions. It is easy to see that for the vast amount of SMB primary applications, public cloud storage performance will be unacceptable. Even something as simple as writing or reading Microsoft Office files will drive employees crazy.
So now that we understand why an SMB shouldn't use cloud storage as primary storage, we have to look at when it makes sense to use cloud data storage services in your small business environment.
When do cloud storage services make sense?
If an SMB is using cloud computing services such as Google Docs, Microsoft Office 365, or SalesForce.com, then it makes sense to store the data from those apps in a cloud storage service. In those cases, the data storage is collocated with the applications. Response time between the application and storage is the same as if the application and storage were in the SMB's location. The key issue here is the response time between the cloud application and the SMB user. In this scenario, the collocated storage is not the bottleneck to user response time. Therefore, if the cloud application performance is adequate, so too is the cloud storage.
If the cloud storage and the application that's using it are collocated, then it makes sense to use cloud storage as SMB primary storage. Otherwise, slow application performance would make using a cloud data storage provider a poor choice for your SMB environment.
About the author: Marc Staimer is the founder, senior analyst, and CDS of Dragon Slayer Consulting in Beaverton, OR. The consulting practice of more than 12+ years has focused in the areas of strategic planning, product development, and market development. With over 30+ years of marketing, sales and business experience in infrastructure, storage, server, software, and virtualization, he's considered one of the industry's leading experts. Marc can be reached at firstname.lastname@example.org.
This was first published in December 2010