Unified storage – more than just SAN/NAS
The topic of NAS/SAN convergence has a lingering presence for one simple reason: it makes sense. In principle, it reduces hardware costs and simplifies storage architecture, making it more flexible, more robust and, most importantly, cheaper and easier to manage. The topic hangs around because, up until now, no one has really architected an affordable unified storage system with a single management interface that delivers on these principles. At the enterprise level, FC SANs can be used as a base on which to build NAS storage silos, providing a form of unified storage architecture. However, in reality there are still two separate systems to manage: The FC SAN and the NAS head. Low cost flexibility is also a phrase that few will associate with a virtualized FC SAN. While the basic costs of FC SAN have dropped in recent years, try adding in additional hosts, remote sites and backup, and the costs escalate dramatically. Add to this the need for FC networking skills and it is clear that this is no mass-market solution. At the other end of the scale, NAS vendors have bolted iSCSI functionality on top of their file system. Again, this is a form of unified storage architecture. But the reality is that pushing IP SAN application storage through a file system is like driving a Ferrari in a traffic jam: it does not actually go any faster. Add a file system crash into the equation, and recovering block storage that was running over the top of NAS can get really nasty. The only area which has seen genuine advances for the SME customer is pure iSCSI SAN. IP SAN really can offer lower hardware costs and deliver flexible connectivity for new storage hosts, new capacity and remote sites, and dramatically simplify backup. And, the vendors that have succeeded in the IP SAN space are those who have developed simple, well-defined GUIs that actually deliver these benefits to the administrator. This last point is the real key: there is no point in having an architecture which is simple in principle but in reality is complex to administer. Administration costs are increasingly the largest part of any company’s storage budget. In the enterprise, economies of scale can lighten the blow but for the small/medium sized business, simplicity is everything. The small/medium sized business data centre has many of the same demands as the enterprise data centre but with only a fraction of the administration budget. Add in the very real small/medium sized business issues of branch office connectivity and remote backup, and with a compound iSCSI/NAS solution, simplicity instantly flies out the window. File systems have to be backed up separately from the underlying iSCSI storage, using two separate systems. Introducing remote sites will lead to separate NAS silos or complex dual tier backup and synchronization. Using what is effectively a fourth-party backup solution can lighten the burden, but naturally, this introduces new costs and a third management interface to do something that can be done with one. There is only one way to produce an effective, affordable, user-friendly unified storage solution. All storage needs to be virtualized at the block level. Then NAS and SAN are run in parallel above this. At the top layer, the administrator needs a single unified interface designed to manage NAS, SAN and the underlying use of virtualization for additional services such as backup and WAN connectivity to remote sites. From this foundation, the all-important single interface delivers all of a business’ storage and replication needs from one console – from a single pane of glass. The administrator still needs an understanding of the basic underlying storage principles, but all of the most common tasks can be run through the one GUI that is designed to perform them. And, with innovative technologies, such as adaptive wizards and task automation, the administrator can do the everyday complex tasks quicker and with less chance of error. One management interface designed to work with one holistic system. Real unified storage. Author: Stefan Schaefer is director of European Operations for RELDATA Inc. He was previously a technical director at BROKAT Technologies Inc. and BROKAT AG, a worldwide supplier of e-business platforms. Schaefer holds a double major in computer science and economics from Germany's prestigious Furtwangen University of Applied Sciences.
•Date: 10th April 2008• Region: World •Type: Article •Topic: IT continuity. |
