HP Microsoft Windows Server 2003 for Itanium-based Systems manual RAID 1+0-drive mirroring

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RAID 1+0—drive mirroring

In a RAID 1+0 configuration, data is duplicated to a second drive.

When the array has more than two physical drives, drives are mirrored in pairs.

In each mirrored pair, the physical drive that is not busy answering other requests answers any read requests that are sent to the array. (This behavior is called load balancing.) If a physical drive fails, the remaining drive in the mirrored pair can still provide all the necessary data. Several drives in the array can fail without incurring data loss, as long as no two failed drives belong to the same mirrored pair.

This fault-tolerance method is useful when high performance and data protection are more important than the cost of physical drives.

NOTE: When there are only two physical drives in the array, this fault-tolerance method is often referred to as RAID 1.

Advantages:

•Has the highest read performance of any fault-tolerant configuration.

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Contents HP Array Configuration Utility User Guide Audience assumptions Contents Diagnosing array problems Getting started Features and system requirementsInstalling ACU This sectionComparison of ACU execution modes Overview for using ACUSetting the execution mode for Microsoft Windows Opening ACU in Local Application mode Choosing an operating modeOpening ACU in Browser mode Http//servername2301Opening ACU through Systems Insight Manager Select Device QueriesTypical Standard mode screen GUI operating modesTypical Configuration Wizards mode screen Completing the configuration process Typical Express Configuration mode screenPossible tasks in Standard Configuration mode Configuring a new controllerUsing Standard Configuration mode Using Express Configuration mode Click Finish Using the configuration wizardsCreating an array Click Create an array, and then click BeginConfiguring a new controller Creating a logical drive Click Create a logical drive, and then click BeginConfiguring a new controller Choices available after opening ACU Modifying an existing configurationModifying a configuration using Standard Configuration mode Clear Configuration Modifying a configuration using Express modeModifying a configuration using the Configuration wizards Click Express Configuration, and then click BeginCreate an array Controller settingsClick Controller Settings, and then click Begin Create a logical drive Delete arrays Click Delete logical drives, and then click Begin Delete logical drivesExpand Array Click Extend logical drive, and then click Begin Extend logical driveMigrate a logical drive Click Migrate a logical drive, and then click BeginRA4x00 controllers Spare managementSelective Storage Presentation Click Spare Management, and then click BeginMSA and Smart Array Cluster storage controllers Configuring switches Click ACU Switch ConfigurationSplitting a mirrored array Recombining a split, mirrored arrayModifying an existing configuration Introduction to scripting in ACU Command line syntaxScripting in ACU Operating modesSample custom input script Cpqacuxe -i FilenameScript file options Description of option categories in ACU scriptingAction Control categoryController category MethodLicenseKey, DeleteLicenseKey ClearConfigurationWithDataLossController RAIDArrayIDRebuildPriority, ExpandPriority SurfaceScanDelayArray category SSPStateDrive Logical Drive categoryOnlineSpare LogicalDriveStripeSize SizeSectors ArrayAcceleratorConnectionName Error reportingSSPAdaptersWithAccess HostModeACU scripting error messages 0-9, !, @, #, *, , , ,, -, , +, , ., /, and space. The ID Current configuration Running the CLI Using the Command Line InterfaceOverview of the ACU CLI Keyword abbreviations Command variableCLI syntax Target variableHiding warning prompts Typical proceduresExample command Querying a deviceSample scenario SyntaxExample Example commandsModifying the controller chassis name Using Selective Storage Presentation Sample scenarioModifying connection names Managing host modes connection profilesExpanding an array Deleting target devicesIdentifying devices Extending a logical driveMigrating a logical drive Target modify raid=01+0156adg? ss=8163264128256default?Managing spare drives Target modify size=#max? forcedChanging the controller cache ratio Changing the Rebuild Priority settingChanging the Expand Priority setting Enabling or disabling the drive cache Changing the surface scan delay timeRe-enabling a failed logical drive Disabling a redundant controller Setting the targetEnabling or disabling the array accelerator Typical scenarioRescanning the system = rescanProbability of logical drive failure Factors involved in logical drive failureProbability of logical drive failure Drive arrays and fault-tolerance methods Drive arraysDrive arrays and fault-tolerance methods Fault-tolerance methods Hardware-based fault-tolerance methodsDisadvantages RAID 0-No fault toleranceAdvantages RAID 1+0-drive mirroring RAID 5-distributed data guarding RAID 6 ADG-Advanced Data GuardingComparing the hardware-based RAID methods RAID RAID 6 ADGAlternative fault-tolerance methods Selecting a RAID methodServer Diagnostics Diagnosing array problemsDiagnostic tools Post messagesAcronyms and abbreviations SSP Index Index