Promise Technology TX4, TX8 user manual RAID 0+1 STRIPING/MIRROR

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RAID 0+1 – STRIPING/MIRROR

Striping/mirroring combines both of the previous array types. It can increase performance by reading and writing data in parallel while protecting data with duplication. At least four drives are needed for RAID0+1 to be installed. With a four-drive disk array, drive pairs are striped together with one pair mirroring the first pair. The data capacity is similar to a standard mirroring array, with half of the total storage capacity dedicated for redundancy. An added plus for using RAID 0+1 is that, in many situations, such an array offers double fault tolerance. Double fault tolerance may allow your data array to continue to operate depending on which two drives fail.

Figure A3. RAID 0+1 striping and mirroring of two drive pairs

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Contents ULTRATRAK100 TX4 ULTRATRAK100 TX8 Trademarks CopyrightImportant Data Protection Information Radio Frequency Interference Statement Table of Contents RAID Page Architectural Description IntroductionFeature Benefit Features and BenefitsConfiguration Install Hard DrivesGetting Started Unpack ULTRATRAK100UltraTrak100 Disk Drive Access TX4 Shown Back of UltraTrak100 TX4 see for TX8 Connecting the Scsi CablesDaisy Chaining Several UltraTrak100s Together Assign a Scsi ID Connect Power Cable and Switch Power onConfigure the ULTRATRAK100 Press SEL to Save Changes Advantages Disadvantages Choosing a RAID LevelRAID 0+1 Characteristics/Advantages DisadvantagesJbod Partition and Format the ArrayDrive Status Indicators MaintenanceIndicator Color Meaning Critical & Offline ArraysWhen a Disk Drive Fails REBUILDING/SYNCHRONIZING Fault Tolerant ArraysReplacing a Disk Drive Module Drive Carrier Drive ReplacementReplacing a Power Supply Module TX8 only Connecting Cables to Disk DriveBack of UltraTrak100 TX8 Type of Interface Name Comments ULTRATRAK100 Front Panel InterfaceConfiguration Mode Error ModeLCD Messages Array FunctionalConfigure Scsi View Status Configure Array Configure CacheView Status View Cache Stats View Controller InfoView Array Information View EnclosureView Controller Information Array 0 Size 12GB Temperature 30C/86FRAID 0 Functional 5009 RPMCreate/Cancel Press SEL to Create Press Exit to Cancel What you can do Auto Array SetupView Drive Assignments Define Array Delete ArrayMaxtor Asng In Ary IBM Asng In Ary No Free Disk What you can doRAID Level 4KB 8KB IBM Assigned Maxtor Free Maxtor FreeWipe out disk Synchronize Array Disable Buzzer Rebuild/Sync Pri. Low Array IDWrite Cache What you can do Write CacheWrite Back Write Thru What you can do Write BackID Selected ModePress Or to move these items on the LCD What you can do Scsi IDContacting Promise Support Technical Support ServicesUSA Tech Support Center European Tech SupportChina Office Pacific Rim Sales OfficeDisclaimer of Other Warranties Limited WarrantyPage Returning Product for Repair USA & Canada Your Responsibilities Introduction to RAID Appendix a Technology BackgroundRAID 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?