Storage in the cloud
Doppler shift or marketing gloss?
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- Google offers hosted office-like applications,
- Amazon offers its SimpleDB, S3 storage service and Elastic Compute Cloud (EC2).
SAAS could be quite a disruption.
Cloud computing or cloud cuckoo land?
This categorisation of massive inter-linked data centres offering web-facing services by Google, Amazon, Yahoo!, Microsoft and others is a description that is inevitably crude. The details of such mega-data centre architectures are kept generally secret, for competitive advantage reasons. The 'cloud' title is determined by the apparent scale of computing power on offer and it's availability as a web-delivered service to end-users (YouTube, MySpace, Facebook) or to business (Google EC2, Amazon SimpleDB).
Cloud computing isn't defined by particular data centre architectures. Nevertheless cloud computing can be seen as a logical evolution of grid and utility computing ideas. The massive petabyte-level scale of cloud storage would bring the cost/GB of storage to the fore and rule out traditional controller-based array building blocks on cost grounds.
A rough consensus view seems to be that clustered NAS systems will be a common cloud storage architecture; the Google-type clustered server+DAS infrastructure is unique to Google and its particularly search-focused needs. A clustered NAS system is more generally applicable and needs to have a very large and global namespace for its files and an infrastructure for organising millions of files, file protection and access.
Cloud storage seems to be quite separate from current SAN and NAS storage because of this controller-less array architecture and a need for a different file system, one that has the scale capacity and actively manages data protection in the storage media it oversees. It has to do that; there are no controllers, meaning no RAID hardware.
Two such file systems have some public presence: GFS from Google and ZFS from Sun.
Can businesses with a need for petabyte-levels of storage use cloud computing storage models? Isilon might argue that some already are. For example its customers in the media area are using clustered NAS systems to stream billions of bytes of video files to their users involved in rendering movies or to their customers.
Other areas where exceptionally large and file-based online data stores are necessary are the pharmaceutical industry and some earth sciences applications which may well use supercomputers.
The attraction of cloud computing is similar parallel processing of supercomputer applications but at much lower cost.
At the other end of the enterprise scale small businesses (SME) could well find cloud-based computing and storage services attractive because it means they don't have to acquire, manage and operate their own IT infrastructure to do those things. It saves them quite a lot of time, enables focus on their core business activities, and saves them money.
Google and Amazon say there are thousands of SME clients for their cloud business-facing services. As these enterprises grow and need more IT services the cloud vendors are in a position to offer more and deny the traditional IT vendors this business. Mid-range and larger businesses may then be attracted to cloud-based services.
It is in this sense that cloud computing could become a quite disruptive technology over time.