Server clustering has traditionally been a solution aimed at boosting processing capabilities as data sets from business and database applications become too large for single machines.
Lately, though, the technology is being deployed more as a storage solution than a raw horsepower one.
This article from Jeff DiCorpo on Infostor highlights many of the backup and recovery advantages of Windows NT clusters. Microsoft placed a premium on high availability in its latest NT Server Enterprise Edition, allowing clustered systems to not only mirror the primary server, but conduct their own operations as well, such as e-mail and Web access. This gives you a lot more bang for the buck than simply provisioning a bunch of backup servers that only see action during a failover.
Data protection becomes a bit problematic in clustered environments, though, as standard network resources are usually insufficient for very large backups. Direct-attached tape backup on each node is probably the best alternative while development continues on a more practical solution.
Clustering solutions are also tapping into the cloud to provide more scalable storage environments. Start-up ParaScale recently unveiled ParaScale Cloud Storage (PCS) software that combines up to several hundred Linux-based servers into a massive parallel storage framework. The package also provides for automatic load balancing and capacity utilization across multiple nodes.
The system is designed for enterprises looking to establish their own private cloud storage or to open it up for public use. A single server acts as a metadata controller, while the remainder are connected via Gigabit Ethernet. File storage is essentially made into a single global namespace for access using NFS, WebDay, HTTP or FTP.
Setting up cloud-based clusters is likely to become easier from a physical standpoint as well, with less impact on the electric bill. Rackable Systems just launched the CloudRack C2 cabinet, which offers densities up to 1,280 cores per cabinet, coupled with the company's Power XE distribution system that provides near-perfect phase balancing and uses an AC-to-DC conversion system to eliminate server-level power supplies and cooling fans. The system eliminates the problem of "stranded power," in which energy going into the rack is wasted.
Clustering is still a complex technology that's best undertaken only with a good consultant or system integrator by your side. But if your data loads are starting to push the envelope of your current environment, clustering offers an efficient means to scale up without investing in a lot of under-utilized hardware.