The Sun StorEdge A3000 subsystem is a redundant array of inexpensive disks (RAID) product. It is offered as a companion unit for the following systems:
Sun Enterprise 3x00, 4x00, 5x00, and 6x00
Sun Enterprise 450 and 250
It is a high performance rack-mounted disk array controller that features redundant power and cooling by incorporating hot-plug technology to support the unexpected loss of one controller, one fan, or one power supply. Failed disk driver can be hot-plugged without stopping I/O activity to the subsystem.
The controller module, which is installed in the subsystem, supports dual SCSI hosts on a 16-bit SCSI-2 bus. In addition, the unit provides the same SCSI-2 bus interface for up to five differential drive trays in the expansion cabinet.
There are two SCSI controllers inside the controller module that use five independent drive channels to manage data distribution and storage for up to thirty-five disk drives. The controllers perform system status and fault detection functions as well.
The controller module combines disk array technology with redundant modular components to provide fast data transfer rates, plus reliable, high-volume data retrieval and storage functions across multiple drives. It works with the RAID Manager software, a disk array management program for configuring, monitoring, and troubleshooting the disk array and provides high-performance disk array management services.
As part of this overall disk management system, the controller module supports the following disk array elements and configurations:
RAID levels 0 (disk striping), 1 (disk mirroring), 0+1 (disk striping plug disk mirroring), 3 (data and parity are striped across a drive group), and 5 (hot spares)
Redundant, dual-active controller configurations
Hot swapable components (controllers, fans, and so on)
Fast write cache
With RAID 3, data and parity are striped across a drive group. One drive is used for redundancy. All other drives are available for storing user data. Figure 2-12 shows a front view of the Sun StorEdge A3000 subsystem.