‘Storage controllers’ or ‘storage computers’ are embedded with processors which are capable of performing functions for the storage system; a handsome amount of functions can be performed. Storage controllers are capable of operating as a node within a cluster of servers in Scale-out storage, but are not limited to this. They can operate as a ‘dual controller’ which will be a redundant pair and also as separate single controllers.
The storage controllers are independent of one another and each controller has a processor and an Input-Output (I/O) path. The processor is tasked with handling the movement of data and other data-related functions such as volume management and RAID. The I/O is responsible for communicating data to the storage network or to the directly-attached servers.
Capabilities of a Storage Controller
The speed and capabilities of the storage controller play a vital role in impacting the performance of the storage array in a modern data center. Data movement functions require fast storage infrastructures. They are tasked with doing the most important work which involves processing and performing functions. The storage controller has to efficiently communicate with the disk drives attached to a storage system to ensure rapid data flow. The numbers of drives hence directly affect the performance of the controller.
Solid State Drives (SSDs) have made the work of storage controllers very fast. The time taken by the controller between drive I/Os in order to perform certain functions has been reduced by huge amounts; latency is almost gone.
Storage controllers are tasked with volume management to ensure the speedy access to data when needed. They also provide ease of access and reliability as data travels at effective speed.
Storage controllers not only perform basic functions such as RAID (redundant array of independent disks) and volume management, but the processors in the storage controllers also dive into a number of complex tasks. Tasks such as snapshots, cloning, thin provisioning and replication are done with high levels of speed.
The first three functions are especially burdensome as they dynamically allocate storage space when the data is being written or changed in the storage system. This takes up a lot of the processors capabilities. They require more power to do the work. So, connecting to the host for capacity pre-allocation and then working in the background to fulfill the storage commitments becomes essential.
Ability and Work of a Storage Controller
Today’s dynamic environment is in search of new and better technology with every passing day. Demands of users revolve around newer innovations to provide the perfect balance for their needs.
Users are searching for technologies capable of providing better performance alongside the ability to work in dynamic environments. Storage controllers provide high levels of performance and are capable of working in different environments; even in Automated Tiering where there is constant movement of data back and forth in between different storage classes. Such an environment requires high performance capability driven storage controllers which need to analyze access patterns and statistics of different applications in order to move data.
Continuous technological advancements provide great growth prospects for storage controllers. With increasing needs for greater performance and requirements of reduction in latencies, storage controllers provide for the needs of the customers. Storage controllers can be added with greater ‘headroom’ to maintain adequate performance as storage systems grow.
Storage controllers hence provide users with added benefits of greater performance and speed with minute additions.