Storage Management

Model

The Array Manager storage model represents the different components in a storage subsystem as either physical or logical storage objects. These objects are displayed in a hierarchical order. A computer object representing a local or remote computer running Array Manager is at the top of the hierarchy for each storage subsystem. The Array Manager GUI can display multiple storage subsystems. You can expand the tree view (display lower levels of the subsystem hierarchy) by clicking on the storage subsystem objects. You can also customize the default tree view.

Arrays

Arrays represent the physical and logical storage subsystems connected to RAID controllers. The array consists of one or more subsystem objects. An example of a subsystem can be a PERC subsystem, which is a RAID controller-specific storage subsystem. A subsystem object consists of two subordinate storage objects:

Physical array — Contains the physical view of storage entities such as controllers, channels, and array disks, as well as physical enclosures and SAF-TE objects.
Logical array — Contains the logical view of array groups. An array group contains array disks and virtual disks.

The fully expanded object hierarchy (right) shows both the Physical Array and the Logical Array. The Physical Array object has a PERC 2/SC controller that contains a single channel (Channel 0) with five array disks. The array disk numbering corresponds with the number of the channel and the SCSI ID.

An array disk is a physical disk controlled by the array controller.

The Logical Array object contains array groups. An array group includes array disks that are controlled by a particular array controller. An array group is named by the number of the array controller it is associated with. For example, array disks attached to Controller 0 belong to Array Group 0. With SCSI RAID controllers, you can create multiple virtual disks from disks in an array group.

A virtual disk is made up of one or more array disks and/or array disk segments presented to an operating system as a single contiguous block of storage space. When you create a virtual disk, you are asked to specify a hardware RAID level.

This is an image of the Array section expanded.


		NOTE: With a redundant Fibre Channel RAID controller, which supports a large number of physical disks, you will need to define one or more disk groups from the array group before creating virtual disks. You then create virtual disks from a disk group rather than from the larger array group. Disk groups are not shown in the image above.

Disks

Disks are simply disk objects recognized by the Microsoft Windows NT or Windows 2000 operating system, including regular hard disks and virtual disks created through Array Manager. This view also includes removable media, such as CD-ROM drives or removable disks, such as Zip disks. Disks can be further classified as one of two types, basic or dynamic.

Basic

Dynamic
Dynamic disks are created by upgrading basic disks using Array Manager. A dynamic disk is a physical disk that can contain dynamic volumes created by Array Manager

Volumes

A volume is a logical entity that is made up of portions of one or more physical disks. A volume can be formatted with a file system and can be assigned a drive letter. The maximum size of a volume depends on the quantity of free disk space and the type of volume selected.

Windows 2000 Disk Management and Array Manager

Disk Management is the built-in disk and volume manager that comes with Windows 2000. This is the Windows 2000 equivalent of Windows NT's Disk Administrator. Disk Management is also known as Logical Disk Manager, or LDM.

Disk Management and Array Manager are related products that come from the same development group. The Array Manager software that runs on Windows 2000 is an upgrade to Disk Management. When you install Array Manager on a Windows 2000 system, it replaces Disk Management and enhances its functionality. Array Manager has the same disk and volume functions as Disk Management, plus the added capability of managing RAID hardware controllers. If you created disks and volumes with Disk Management before installing Array Manager, those same disks and volumes can be managed by Array Manager without any adjustments.