TechTarget has an interesting article on the difference and pro’s vs cons of scale-out NAS and scale-up NAS systems.
Scale-out NAS systems are used extensively by many of today’s leading organisations including Facebook, Myspace and the BBC iPlayer. Scale-out NAS is a storage architecture which is changing the way companies store gigabytes and petabytes of data. Scale-out NAS has a totally different structure and is typically designed for rapid data growth in file or unstructured data environments, without the performance or management limitations associated with traditional NAS / SAN systems.
“One of the main attractions of traditional NAS is its simplicity. The systems are easy to install, configure, manage and operate, especially in environments of modest scale. Product upgrades in this “scale-up” category follow the traditional speeds and feeds pattern of replacing a box with faster processors and larger-capacity storage.
Scale-up products are generally mature and have plenty of features and add-on software for data protection, business continuance and storage efficiency. Options include snapshots, one-to-many and many-to-one replication, remote replication and remote snapshots, thin provisioning, deduplication and compression.
Traditional NAS systems can be cost-effective and reliable, particularly for small- to medium-sized businesses (SMBs). They help to consolidate file servers and centralize data protection. They may also be tightly integrated with common business applications and their native management consoles.
The main downside of traditional NAS is its inability to scale beyond the limits of the system, forcing customers to purchase additional, separately managed boxes when they need to add capacity. Capacity on these NAS boxes may be underutilized if users aren’t able to add capacity because they’ve run out of performance or bandwidth.
Scale-out NAS systems carry the advantage of scaling capacity and performance on an as-needed basis, far beyond the limits of traditional scale-up NAS. They typically distribute data across many storage controllers, and the systems’ clustered architectures ensure high availability.
Once the system is up and running, scale-out NAS brings the huge advantage of being able to manage and move petabytes of data under a single distributed file system and global namespace, and the systems generally support large volumes. Users, in turn, can maintain floor space requirements, power and cooling costs, and management staff.
Some scale-out NAS systems carry fairly substantial licensing fees that are tacked onto the incremental costs associated with adding equipment. Plus, scale-out systems tend to lack the feature/functionality of well-established scale-up NAS systems, at least at the moment.
For instance, a scale-out NAS system might offer remote replication, but only the asynchronous variety — not one-to-many or many-to-one functionality. The vendor also might have optimized the system to handle large files rather than huge numbers of small files and might not offer unified block and file storage capability.”
Read the whole article at: searchstorage.techtarget: NAS options: Pros and Cons of scale-out and scale-up