Cloud providers need to fill the niche for web-hosted, web-application delivered file storage. Otherwise cloud storage will be relegated to backups and disaster recovery, says Lori MacVittie.
Many years ago, when I was coding in Smalltalk IV for a little-known mid-western US telecoms provider, I had — as everyone does at some point — a quirky colleague.
Apparently he was also prescient because one day he took a very old hard drive, taped two dimes to it, and hung it from the ceiling. When we asked, "What's that?" he smiled cockily and said, "That's Dasdi in the sky with dimes on." Go ahead, groan. We did.
For those too young to understand, Dasdi is direct access storage device initialisation — storage, in other words. And of course if you aren't familiar with the 1960s Beatles song, Lucy in the Sky with Diamonds, his awful pun will be lost on you.
We've all long since moved on, but from time to time his pun creeps into my head. But when it last did so, instead of making me shake my head, it suddenly seemed almost prophetic. Dasdi, or storage, in the sky, or the cloud, with dimes on, meaning cheap. Then I thought, "The whole cloud storage thing has come full circle, hasn't it?"
Storage in the cloud Long before there was even a hint of storage in the sky, there was NFS [network file system]. And using NFS we could mount remote storage — even across the internet — and act as though it were local. We had storage in the cloud of a sort.
Now along comes cloud computing and suddenly our nice, simple NFS interface has been turned into a set of web services. Many will say that development is good, because not every system supports NFS. Besides, you can't ask users to mount remote drives.
In any case, users don't use clouds; they use applications. Those applications may take advantage of services such as cloud storage services, but users never interact directly with those interfaces. The application might, and the server itself might, but not the user.
And therein lies the truth about cloud storage and its web interfaces. It's not meant to be treated like real storage in the sense that it can be part of your storage area network (SAN). It's meant to be a backup, or a nice place for users to store their files. It's consumer grade, not enterprise grade, and even with the help of a cloud storage gateway it's not necessarily going to replace your current storage network architecture.
Cloud storage services are designed to be accessed via the web. They're not designed for real-time access unless that real-time access is part of a web application and the storage service is hosting images or other media.
Disaster-recovery, business-continuity In any case, the problem is that from the administrative side, a simple NFS, CIFS [common internet file system] or SMB [server message block] mount to a location in the cloud would probably be a perfect component to many disaster-recovery, business-continuity, or efficient storage strategies. It would also alleviate the need to...
...rewrite a lot of scripts and management-type applications. After all, most operating systems don't let you mount a web service — at least not yet.
The storage gateway is designed to address the disparity between implementation and service. It is a wonderful device that fills a hole created by standards and commoditisation of cloud and networked storage.
There needs to be a way to bridge the gap between the protocols we use inside the organisation and the emerging cloud services standards.
Cloud storage has attempted to standardise on some well-known web service protocols, such as HTTP, Soap and XML, but this move doesn't address the core issue of how servers and desktops actually use storage every day. Servers and desktops alike use traditional storage protocols or networked storage protocols, but not necessarily web application protocols.
Thus there needs to be a way to bridge the gap between the protocols we use inside the organisation and the emerging cloud services standards. If that need means cloud gateways must become controllers instead of gateways — or vice versa — so be it.
Support for legacy and emerging access methods But if cloud storage is going to be integrated and useful to the organisation, it must support legacy and emerging methods of accessing the storage it manages.
Unless cloud storage providers are planning on filling the niche for web-hosted, web-application delivered file storage and want to avoid being relegated to a third tier in a hierarchical storage network suitable only for backups and disaster recovery, they need to determine how cloud storage can address the issue of how storage is actually used in the datacentre.
That requirement means bridging the gap between the protocols that make up today's highly complex storage architectures and those that allow access to cloud storage services.
Until then, cloud storage services will remain not even second class but a third-class citizen in the datacentre.
Lori MacVittie is responsible for application services education and evangelism at application delivery firm F5 Networks. Her role includes producing technical materials and participating in community-based forums and industry standards organisations. MacVittie has extensive programming experience as an application architect, as well as in network and systems development and administration.
