A storage subsystem is a storage entity managed by storage management software. A storage subsystem consists of a collection of both physical components and logical components. (The term "storage subsystem" replaces the term "RAID Module," which was used in previous versions of this storage management software.)
The physical components of a storage subsystem are described below:
Component |
Description |
Controller |
A controller consists of a board and firmware that controls the drives and implements the storage management functions. |
Controller Enclosure |
A controller enclosure contains one or more controllers, power supply canisters, fan canisters and other supporting components in a single enclosure. |
Drive |
A drive is an electromagnetic mechanical device providing the physical storage media for data. |
Drive Enclosure |
A drive enclosure contains a set of drives, power supply canisters, fan canisters, ESM canister(s) and other supporting components in a single enclosure. |
Controller/Drive Enclosure |
Some storage subsystem models combine both controller and drive components in the same enclosure. |
The drives in the storage subsystem provide the physical storage capacity for data. Use the storage management software to configure the physical capacity into logical components (arrays, logical drives, and storage subsystem partitions). These components are the tools you use to configure, store, maintain, and preserve data on the storage subsystem. The logical components of a storage subsystem are described below:
Component |
Description |
Array |
An array is a set of drives that are logically grouped together by the controllers in a storage subsystem for the purposed of creating one or more logical drives for data storage. |
Logical Drive |
A logical drive is the basic structure you create on the storage subsystem to store data. A logical drive is configured across an array with a specific RAID level to meet application needs for data availability and I/O performance. A logical drive is seen by the operating system as one drive. |
Free Capacity |
Free capacity is a contiguous region of unused capacity on a designated array. The space can be used to create one or more logical drives. Note: In the Subsystem Management Window Logical View, free capacity is shown as Free Capacity Nodes. Multiple Free Capacity nodes can exist on an array. |
Unconfigured Capacity |
Unconfigured capacity is capacity that is present in the storage subsystem from drives that have not been assigned to an array. The space can be used to create new arrays and logical drives. Note: In the Subsystem Management Window Logical View, unconfigured capacity is shown as an Unconfigured Capacity Node. |
Storage Subsystem Partition |
A storage partition is a logical grouping of one or more storage subsystem logical drives. Storage Partitioning allows you configure a single storage subsystem as multiple virtual storage subsystems up to the maximum value enabled. Access to a storage partition can be restricted to particular hosts or groups of hosts by defining a set of logical drive-to-LUN mappings. A logical drive-to-LUN mapping defines which host or host group will have access to a particular logical drive in the storage subsystem. |