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Disk drive carrier for high reliability ATA disk drive enclosure

IP.com Disclosure Number: IPCOM000010461D
Original Publication Date: 2002-Dec-05
Included in the Prior Art Database: 2002-Dec-05
Document File: 3 page(s) / 24K

Publishing Venue

IBM

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Disk drive carrier for high reliability ATA disk drive enclosure

Disclosed is a circuit for a high reliability disk drive enclosure with standard parallel ATA hard disk drives. This circuit provides drive status, a drive start-up control function, and a dual serial ATA drive interface for an enclosure's redundancy.

A storage subsystem is made of an enclosure which contains a number of hard disk drives, or made of multiple enclosures connected together when the storage capacity needs to be expanded. In general, a high reliability storage subsystem using FC-AL hard disk drives or SCSI hard disk drives is expensive, while it is known that a storage enclosure contains standard parallel ATA hard disk drives can reduces the storage subsystem cost. However, the current parallel-ATA drive enclosure does not place importance on high reliability functions that are supported on the FC-AL or SCSI drive enclosure, such as a redundant data path, drive spin-up control for delayed start, an emergency power off warning, and etc.

Figure 1 illustrates how drives are connected to a dual controller in a disk drive enclosure. Both the primary I/O controller and the secondary I/O controller perform read and write operations to hard disk drives through the dual channel serial-ATA interface on the disk drive carrier, and some control signals go to the disk drive carrier for high reliability functions.

Disk Enclosure

Primary I/O Controller

Data

I/O Control

Power Control

Disk Status

Disk Carrier

ATA Disk Drive

Spin-up Control

I/O Interface

Data

Secondary I/O Controller

Disk Presence & Status

Figure 1. Storage Subsystem Overview

The block diagram of the disk drive carrier is given in figure 2. There are three major control circuits specified below:

A disk control circuit provides the spin-up control to avoid all drives to start spin-up immediately when the enclosure powers on. At a parallel-ATA drive's power-on, it does not start spin-up during the drive reset signal is enable within a period of time that is specified by the disk drive ID or control signals. Therefore disk drives can be started sequentially that is called delayed start. This circuit also takes care of the emergency power off warning that is notified to shut down the enclosure power in a short time. When this warning is received, the disk controller circuit enables the drive reset signal to stop the read and write operation on the disk drive for safe power-off without damage to the written data in disk drives.

In addition, this circuit gives a disk drive presence signal and a disk carrier failure signal to the I/O controllers.

A data path switch establishes a electrical connection between the disk drive and the active I/O controller. In the normal condition, the primary I/O controller performs a...