Get More Value From a Cloud Storage Gateway

What is a CSG?
A cloud storage gateway is software that runs on hardware or in a virtual machine that moves data out to one of the many storage-as-a-service providers. CSGs exist to be a holding tank within your LAN until data is moved to your cloud storage vendor. By residing within the LAN, CSGs enable local writes to execute as fast as possible without relying on a slower WAN connection between you and the cloud to write your data.

I have seen a few different approaches to how the local data is dealt with, but in all cases the data is accessible to the user and application even if it is no longer in the local CSG storage. In all cases the software moves the data to the cloud, and when a read request comes in, the CSG will fetch the data to fulfill the read request.

Here is a very simple use case that might help you to see the benefits of using a CSG.

Let's assume that you are not using your great SharePoint site, and instead you're just using well-organized file shares on a CSG. You access your home drive for your documents and pull down the latest version of a Word document that is 320KB. The request is processed through the CSG, which has more than a 1MB connection to the cloud. Because the requested file is only 320KB the request is filled without you even knowing it was pulled down from cloud storage. You can then view, open and edit the file even though it is not in the local LAN.

That's a high-level overview of what CSGs can do. There are several features and capabilities that can make cloud storage gateways more effective. So, what features make good sense with a CSG?

1. De-Dupe Some cloud vendors charge by the byte for sending data and storing it. The more data you put in the cloud, the more you pay. Deduplication capabilities that are built into a cloud storage gateway can significantly reduce the amount of data to be transferred and stored. So if your CSG can reduce your data footprint by 5x for example, that represents a five-fold reduction of your cloud storage bill.

2. Bandwidth control This is very important because users might share the Internet connection and CSG for an application like Salesforce.com. You want to make sure that the CSG does not cripple the Internet connection and prevent users from accessing Salesforce.com or other essential systems during normal working hours. Bandwidth control is a key feature for preserving access and reliability.

3. Bandwidth control on a schedule It's great that I have bandwidth control and I won't cripple my Internet connection, but at night when my users are not in the office I want to open up the bandwidth for the CSG. For example, for the hours of 7 a.m. to 7 p.m., I would want to reserve 1 MB of my 4 MB connection usable by the CSG.

This allows 3 MB of my Internet connect for my users. From 7 p.m. to 7 a.m., during off hours, I would want 3.5 MB of my 4 MB connection available to allow the CSG to get as much data to the cloud as fast as possible while my users are not around. It should be easy for you to schedule bandwidth adjustments and change them as necessary.

4. Being able to delete from the cloud Some vendors cannot remove data from the cloud that you delete locally on the CSG. These vendors have workarounds available and are looking to solve this problem soon. Until they do, not being able to effectively remove data from the cloud will cost you more money for storage, so the ability to delete from the cloud is a money-saving feature.

5. Being able to run as a VM Being able to just toss up a VM for this function makes sense because you're able to utilize your hypervisor's built-in redundancy and your SAN storage for the CSG. Instead of needing a new piece of hardware in your data center for your CSG, let's use what you have.  

Stay tuned! Next, I'll talk about image-based backups and using a cloud storage gateway.

Posted by Jason Mattox on 01/14/2011 at 12:49 PM