Part 2: Storage as a Service - Clouds of Data

collaboration, off-line backup and storage (read "tape"), to disaster recovery are all possible in The Cloud.

Naturally, putting one's sensitive corporate information into The Cloud brings up the question of security and integrity.  I'm not too sure that I'd hire a law firm that stored its attorney-client privileged information on a Google service.  Let me think about that for..nah, that isn't happening.  But there are firms who do just that (allegedly).  Just count me out as one of their potential clients.

Okay, let's get on with this week's installment.  Take it away, Mr. Koehler.


Part 2: Storage as a Service - Clouds of Data

Usage models for SaaS

Now that we have clarified the issues of how SaaS can be embodied, what would someone use it for? The blatant response of 'to store data stupid' is not sufficient. Most certainly that is an answer, but it turns out that the use case models are much more varied and interesting. At this point, I think that it is fruitful to discern between two major user populations - Residential & Business, with business including education and government institutions. The reason for the division is the degree of formality in usage. In most residential use models, there are no legal compliance issues like SOX or HIPPA to deal with. There may be confidentiality and security issues but as indicated earlier these issues are easier to address in a semi-private or private SaaS.


Business and Institution use models

Virtual Tape Library SaaS

The figure below illustrates a simple VTL SaaS topology. The basic premise is to emulate a physical tape drive across the network with connectivity provided as an iSCSI target to the initiator, which is the customer's backup software. With the right open system VTL, the service can be as easy as a new iSCSI target that is discovered and entered into the backup server. With no modifications to existing practices or installed software, the service matches well with organizations that are tape oriented in practice and are looking for an effective means of secondary off site copies. Tapes can be re-imported back across the network to physical tape if required in the future.

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Figure 1. A Simple VTL SaaS

D2D SaaS

Disk to disk SaaS offerings basically provide an iSCSI target of a virtual disk volume across the network. In this type of scenario the customers existing backup software simple points to the iSCSI target for D2D backup or replication. Again, the benefit is that because the volume is virtualized and hosted, it effectively addresses off site secondary data store requirements. In some instances that may require CPE, it can even be used in tandem with next generation technologies like continuous data protection and data reduction methods, which moves towards the Hosted Disaster Recovery end of the spectrum. The figure below shows a D2D SaaS service offering with two customers illustrated. One is simply using the service as a virtual disk target. The other has an installed CPE that is running CDP and data reduction resulting in a drastic improvement on the overall required bandwidth.

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Figure 2. A D2D SaaS


Collaborative Share SaaS

Another use model that has been around for a long time is collaborative sharing. I say this because I can remember better than ten years ago placing a file up on an FTP server and then pasting the URL into an email that went out to a dozen or so recipients. Rather than plug up the email servers with multiple copies of large attachments. Engineers have a number of things in common regardless of discipline. First is collaboration. A close second though is the amount of data that they typically require in order to collaborate. This type of model is very similar to the FTP example except that it is enhanced with a collaborative portal that might even host real time web conferencing services. The storage aspect, though of primary importance to the collaboration is now a secondary supporting service that is provided in a unified fashion out to the customer via a web portal. The figure below shows an example of this type of service. Note that in reality there is no direct link between the SaaS and the Web Conferencing application. Instead they are unified and merged by a front end web portal that the customer sees when using the service. On the back end a simple shared virtual network drive is provided that receives all content that is posted by the collaborative team. Each may have there own view and sets of folders for instance and each can share them with one individual, or with a group, or with everyone. This type of service makes a lot of sense for this type of community of users. In fact, any user community that regularly exchanges large amounts of data would find value in the type of use model.

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Figure 3.  A Collaborative Share Service


Disaster Recovery as a Service (DRaaS)

There are times when the user is looking for more than simple storage space. There is a problem that is endemic in small and medium business environments today. There is minimal if any resident IT staff and even less funding to support back end secondary projects like disaster recovery. As a result many companies have BC/DR plans that are woefully inadequate and often would leave them with major or even total data loss in the event of a key critical system failure. For these types of companies using an existing network provider for warm standby virtual data center usage makes a lot of sense. The solution would most probably require CPE to be installed, but after that point the solution could offer a turnkey DR plan that could be tested at regular scheduled intervals for a per event fee.


The big advantage of this approach is that the customer can avoid expanding IT staff and addresses a key issue of primary importance, which is the preservation of data and system up time.


Obviously, this type of service offering requires a provider who is taking SaaS seriously. There is a Data Center required where virtual resources are leased out and hosted to the customer as well as the IT staff required to run the overall operations. As shown by the prevalence of vendors providing this type of service, even with the overhead, it does have an attractive business model that only improves with expanded customer base.

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Figure 4. DRaaS implementation


Residential Use Models

PC Backup & Extra Storage

This type of SaaS offering is similar to the virtual disk service (D2D) mentioned above. The important difference is that it is not iSCSI based. Rather it a NAS virtual drive that is offered to the customer through some type of web service portal. Alternatively, it could be offered as a mountable network drive via Windows Explorer™. The user would then simply drag the folders that they want to store into the cloud onto that network drive. If they use backup software they can with a few simple modifications copy data into the cloud by pointing the backup application to the virtual NAS drive. Additionally, this type of service could support small and medium businesses that are NAS oriented from a data storage architecture perspective. In the figure below, a NAS SaaS is illustrated with a residential user who is using the service to store video and music content. Another user is a small business that is using the service for NAS based D2D backup. Both customers see the service as a mapped network drive (i.e. F or H:). For the residential customer it is a drive that content can be saved to, for the business customer it is a NAS target for its backup application.

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Figure 5. NAS SaaS


Collaborative Share

More and more, friends and family are not only sharing content, but creating it as well. Additionally, most of it is in pictures, music and video. All files of huge size. This results in a huge amount of data that needs to be stored but also needs to be reference able in order to be shared with others. The widely popular YouTube™ is a good example of such a collaborative service. Another example is FaceBook™, where users can post pictures and video to their walls and share them with others as they see fit. As shown in the figure below, SaaS is an embedded feature of the service. The first user posts content into the service there by using the SaaS feature. Then the second user receives the content in a streaming CDN fashion. The first user would post the content via the web service portal (i.e. their wall).The second user would initiate the real time session via the web service portal by clicking on the posted link and view the content via their local installed media player. Aside from the larger industry players, there is a demand for more localized community based collaborative shares that can exist with art and book communities, student populations, or even local business communities.

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Figure 6. Collaborative Share for Residential


- Ed Koehler