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A simple low cost IDE RAID 1 Autonomic implementation

IP.com Disclosure Number: IPCOM000019259D
Original Publication Date: 2003-Sep-08
Included in the Prior Art Database: 2003-Sep-08

Publishing Venue

IBM

Abstract

Many of todays popular OS's provide native support for software mirroring (Raid 1). Although software mirroring support can impact disk write performance since two write operations are needed at the system level to insure that the data gets written to both disks, some customers or market segments find this performance degradation acceptable given the added insurance they get with the redundancy. The problem with software mirroring is that an overt action is needed to continue to make a system function (or boot) in the event that the primary HDD on the ATA interface has had a electronics failure. This overt action may involve the IT Admin swapping jumpers on the ATA Slave device to make it a Master. This is required due to the design of the ATA interface which requires the presence of a master device in order for a slave device to operate properly. What is needed is an autonomic solution which detects a defective ATA Master device, disables it from being the master and automatically reconfigures the slave device to become the master device. In this manner, the system practicing the present invention, recovers to the backup copy of the HDD, thus realizing minimal down time. POST needs to know the state of the cable, try primary disk, get time out, set flags in system and generate alert (could be via the RSA), flip cable lines, issue IDE reset on IDE port, wait for sync time as per the ATA spec, retry boot on next disk, boot to OS, flag offline disk at OS agent level.