Scale-out storage is a network-attached storage (NAS) architecture in which the total amount of disk space can be expanded through the addition of devices in connected arrays with their own resources.
In a scale-out system, new hardware can be added and configured as the need arises. When a scale-out system reaches its storage limit, another array can be added to expand the system capacity. Scale-out storage can harness the extra storage added across arrays and use added devices to increase network storage capacity, adding performance and addressing the need for additional storage.
Before scale-out storage became popular, enterprises often bought storage arrays much larger than needed to ensure that plenty of disk space would be available for future expansion. If that expansion never occurred or the storage needs turned out to be less than anticipated, much of the originally purchased disk space went to waste.
With a scale-out architecture, an organization can make a smaller initial investment because it does not have to consider potential long-term needs. If the storage requirements increase beyond the original expectations, new arrays can be added as needed, essentially without limit.
Scalability is the capacity for some types of systems to continue to function properly when they change in size or volume to meet a specific user need. In some contexts, scalability refers to the ability to meet higher or lower demands of a storage platform. In a storage context, however, rescaling usually refers to responding to a demand for increased capacity.
There are two main approaches to rescaling storage.
Scale-out storage, or horizontal scalability, is the ability to connect multiple storage elements, such as storage arrays, so that they work as a single logical unit. With scale-out storage, there can be many geographically separated nodes.
By contrast in the scale-up versus scale-out debate, the scale-up approach is an example of vertical scalability. This is the ability to increase the capacity of existing hardware or software by adding resources to a physical system.
An example of this is adding processing power or memory to a server to make it faster. In the case of storage systems, it means adding more devices, such as disk drives, to an existing storage array when more capacity is required.
The advantages of scale-out storage include the following:
Some of the more difficult parts of scale-out storage are the following:
With a scale-out system, adding capacity involves implementing a single cluster or as many clusters as requirements dictate. Each device, or node, includes storage capacity. It may be in the form of multiple drive spindles and may have its own processing power and input/output bandwidth. With these resources, as storage capacity increases, performance also increases.
Scale-out NAS grows when storage managers add clustered nodes. These are often X86 servers with a special OS and storage connected through an external network. Nodes may be connected for intercommunication through a high-speed backplane or a network such as Ethernet.
Users administer the single cluster as one system and manage the data through a global namespace or distributed file system, so they do not have to worry about the actual physical location of the data.
Scale-out storage applications and workload types include the following:
Scale-out storage is appropriate for backup and recovery, because with those storage devices, mission-critical data and databases are often located on premises and remotely. This is important to minimize the likelihood of a loss of primary storage during a disruption.
The main difference between scale-out storage and object storage is that scale-out is an architecture, whereas object storage is a format, like block and file formatting.
Object storage is designed for large quantities of unstructured data. Pieces of data are formatted into objects and stored in a specific location with metadata as a bundling component for quick retrieval and storage.
Like block storage and file storage, object storage can use most types of storage platforms. It is used for applications such as the following:
User requirements must be understood when selecting the type of storage technology. In the case of unstructured data, such as emails, images and videos, object storage may simplify the storage and retrieval of large data quantities. As a result, the choice of storage device becomes an important consideration.
As the amount of data increases, storage pools using scale-out storage architectures may be suitable, so long as the devices are able to manage the data growth. If the nature of the data objects is unique, it may be better to use a scale-up approach.
Cloud storage can meet virtually any storage requirement and architecture. For example, scale-out storage using NAS and server-based devices can be implemented in public cloud and private cloud environments.
By using cloud storage, organizations don't need to buy additional floor space to house storage equipment. They use less power and cooling, minimize upfront investment and hand storage management to the cloud provider.
Cloud storage can serve the following applications:
As with any storage technology upgrade, due diligence is needed. The following is a list of steps to perform when considering scale-out data storage solutions:
Scale-out storage is an important part of storage and data management. Learn more about how to effectively manage data storage.
12 Sep 2022