The disk drives in your provide the physical storage capacity for your data. Before you can store data, you must configure the physical storage capacity into components, known as and .
The array is a set of disk drives that the collects together. The array has these characteristics:
The logical drive is a logical entity that your uses to store data. The array can hold one or more logical drives. You create logical drives from in the array.
Keep this information in mind to help you configure your storage subsystem capacity:
These examples show that if you change your configuration choices, those choices can cause redundancy of your data.
Example 1 – No
As the system administrator, you must manage a storage subsystem that is made up of three expansion drawers. The first two expansion drawers hold SAS disk drives. The remaining expansion drawer holds SATA disk drives. Each expansion drawer has a maximum of 12 disk drives.
To meet your storage needs, configure your storage subsystem so that arrays that contain multiple logical drives are created for your key business departments, for example, IT, Marketing, and Finance.
This example shows how to configure your storage subsystem under these conditions. You have decided to use the SATA disk drives to configure the arrays for IT and Finance. You can use the SAS disk drives to configure the arrays for the Marketing department.
You also will use flashcopy logical drives in the future. You must make sure that some unconfigured capacity exists in the form of unassigned disk drives. You will use the unconfigured capacity to create flashcopy repository logical drives to store flashcopy-related information.
Use these configuration options to obtain the storage requirements for this example:
No tray loss protection exists for the expansion drawers. No hot spare disk drives have been provided to the specified arrays. Thus, you could lose accessibility to the data on your array; for example, if a total loss of communication exists with a single expansion drawer. This loss can be loss of power to the expansion drawer or failure of both environmental services monitors (ESMs).
Example 2 – Enclosure Loss Protection
As the system administrator, you must manage a storage subsystem made up of three expansion drawers. Each expansion drawer supplies a maximum of 12 disk drives.
To meet your storage needs, configure your storage subsystem so that arrays containing multiple logical drives are created for your key business departments, for example, IT, Marketing, and Finance. Also, make sure that enclosure loss protection is configured.
This example shows how to configure your storage subsystem under these conditions. You also will use flashcopy logical drives in the future. You must make sure that some unconfigured capacity exists in the form of unassigned disk drives in the storage subsystem. The unconfigured capacity will be used to create flashcopy repository logical drives to store flashcopy-related information.
Use these configuration options to obtain the storage requirements for this example:
Use these configuration options to protect against loss of the expansion drawer for the defined arrays. Even if a total loss of communication with a single expansion drawer occurs, you still have access to the data on your arrays.