Promise Technology TX8 REBUILDING/SYNCHRONIZING Fault Tolerant Arrays, When a Disk Drive Fails

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UltraTrak100 TX4 and UltraTrak100 TX8 User Manual

A non-fault tolerant array goes "offline" when a drive is removed or fails. Since the array is not fault tolerant, the data stored in the array is no longer accessible. If the drive was removed, then it should be replaced to restore accessibility to the array. If the drive failed, then the entire array must be deleted and re-initialized since all data is considered lost.

REBUILDING/SYNCHRONIZING FAULT TOLERANT ARRAYS

Though a critical array can continue storage operations, it no longer offers fault tolerance and should be addressed as soon as possible by replacing the missing or failed drive(s).

Rebuild takes a replacement drive, assigns it to the array, and then writes the redundancy data to it. Once the rebuild process is complete, the array status is upgraded from “critical” to “functional” and fault tolerance is restored.

Synchronization is a preventative maintenance measure used to avoid problems with data integrity. Synchronizing simply recalculates redundant data (similar to the rebuild process) and matches the data on the drive(s).

To synchronize the array, go to the Configuration menu and select Configure Array; then select Advance Features and choose Synchronize Array.

WHEN A DISK DRIVE FAILS

The UltraTrak100 provides both audible and visual indicators alerting you of a drive failure. The following occur when a disk drive fails or goes offline:

Continuously produces short beeps every two seconds when a drive fails.

Continuously produces long beeps every 15 seconds when a drive is offline.

The Array LED on the front panel is yellow.

The disk drive Status LED (inside front panel door) is red.

The LCD displays a status message about the failure.

REPLACING A DISK DRIVE MODULE

UltraTrak100 disk drive modules should not be removed unless it has been determined that a drive in the array has failed.

Generally, a disk drive that is a member of a fault tolerant array may be replaced at any time without affecting the availability of data to the system. Depending on the RAID type, drive removed, and type of access, performance may be reduced until the drive is replaced.

Disk drives may be replaced while UltraTrak100 is running; special circuitry is designed into the UltraTrak100 that protects the components and notifies the processor.

Only a failed drive should be removed from the array. Removing any other drive may cause the array to become unavailable. The replacement drive must be of equal capacity or larger than the failed drive.

In arrays where a hot spare is already installed, the hot spare automatically replaces the failed drive. When the failed drive is replaced, the new drive becomes the new hot spare.

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Contents ULTRATRAK100 TX4 ULTRATRAK100 TX8 Important Data Protection Information CopyrightTrademarks Radio Frequency Interference Statement Table of Contents RAID Page Introduction Architectural DescriptionFeatures and Benefits Feature BenefitInstall Hard Drives ConfigurationGetting Started Unpack ULTRATRAK100UltraTrak100 Disk Drive Access TX4 Shown Connecting the Scsi Cables Back of UltraTrak100 TX4 see for TX8Daisy Chaining Several UltraTrak100s Together Connect Power Cable and Switch Power on Assign a Scsi IDConfigure the ULTRATRAK100 Press SEL to Save Changes Choosing a RAID Level Advantages DisadvantagesCharacteristics/Advantages Disadvantages RAID 0+1Partition and Format the Array JbodMaintenance Drive Status IndicatorsIndicator Color Meaning Critical & Offline ArraysReplacing a Disk Drive Module REBUILDING/SYNCHRONIZING Fault Tolerant ArraysWhen a Disk Drive Fails Drive Replacement Drive CarrierConnecting Cables to Disk Drive Replacing a Power Supply Module TX8 onlyBack of UltraTrak100 TX8 ULTRATRAK100 Front Panel Interface Type of Interface Name CommentsError Mode Configuration ModeLCD Messages Array FunctionalView Status View Status Configure Array Configure CacheConfigure Scsi View Controller Info View Cache StatsView Array Information View EnclosureView Controller Information Temperature 30C/86F Array 0 Size 12GBRAID 0 Functional 5009 RPMCreate/Cancel Auto Array Setup Press SEL to Create Press Exit to Cancel What you can doView Drive Assignments Define Array Delete ArrayNo Free Disk What you can do Maxtor Asng In Ary IBM Asng In AryRAID Level 4KB 8KB Maxtor Free IBM Assigned Maxtor FreeWipe out disk Synchronize Array Disable Buzzer Array ID Rebuild/Sync Pri. LowWrite Cache Write Cache What you can doWrite Back Write Thru What you can do Write BackMode ID SelectedScsi ID Press Or to move these items on the LCD What you can doTechnical Support Services Contacting Promise SupportUSA Tech Support Center European Tech SupportPacific Rim Sales Office China OfficeLimited Warranty Disclaimer of Other WarrantiesPage Returning Product for Repair USA & Canada Your Responsibilities Appendix a Technology Background Introduction to RAIDRAID 1 Mirroring RAID 0+1 STRIPING/MIRROR RAID 3 Block Striping with Parity Drive RAID 5 Block and Parity Striping Jbod Spanning Appendix B Frequently Asked Questions Why can’t I see the drives on the UltraTrak100 under FDISK?