HP Microsoft Windows Server 2003 for Itanium-based Systems manual

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With an array controller installed in the system, the capacity of several physical drives can be combined into one or more virtual units called logical drives (also called logical volumes and denoted by Ln in the figures in this section). Then, the read/write heads of all the constituent physical drives are active simultaneously, reducing the total time required for data transfer.

Because the read/write heads are active simultaneously, the same amount of data is written to each drive during any given time interval. Each unit of data is called a block (denoted by Bn in the figure), and adjacent blocks form a set of data stripes (Sn) across all the physical drives that comprise the logical drive.

For data in the logical drive to be readable, the data block sequence must be the same in every stripe. This sequencing process is performed by the array controller, which sends the data blocks to the drive write heads in the correct order.

A natural consequence of the striping process is that each physical drive in a given logical drive will contain the same amount of data. If one physical drive has a larger capacity than other physical drives in the same logical drive, the extra capacity is wasted because it cannot be used by the logical drive.

The group of physical drives containing the logical drive is called a drive array, or just array (denoted by An in the figure). Because all the physical drives in an array are commonly configured into just one

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Contents HP Array Configuration Utility User Guide Audience assumptions Contents Diagnosing array problems This section Features and system requirementsInstalling ACU Getting startedComparison of ACU execution modes Overview for using ACUSetting the execution mode for Microsoft Windows Choosing an operating mode Opening ACU in Local Application modeHttp//servername2301 Opening ACU in Browser modeSelect Device Queries Opening ACU through Systems Insight ManagerGUI operating modes Typical Standard mode screenTypical Configuration Wizards mode screen Typical Express Configuration mode screen Completing the configuration processPossible tasks in Standard Configuration mode Configuring a new controllerUsing Standard Configuration mode Using Express Configuration mode Click Create an array, and then click Begin Using the configuration wizardsCreating an array Click FinishConfiguring a new controller Click Create a logical drive, and then click Begin Creating a logical driveConfiguring a new controller Choices available after opening ACU Modifying an existing configurationModifying a configuration using Standard Configuration mode Click Express Configuration, and then click Begin Modifying a configuration using Express modeModifying a configuration using the Configuration wizards Clear ConfigurationCreate 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 Migrate a logical drive, and then click Begin Extend logical driveMigrate a logical drive Click Extend logical drive, and then click BeginClick Spare Management, and then click Begin Spare managementSelective Storage Presentation RA4x00 controllersMSA and Smart Array Cluster storage controllers Click ACU Switch Configuration Configuring switchesRecombining a split, mirrored array Splitting a mirrored arrayModifying an existing configuration Operating modes Command line syntaxScripting in ACU Introduction to scripting in ACUCpqacuxe -i Filename Sample custom input scriptDescription of option categories in ACU scripting Script file optionsMethod Control categoryController category ActionRAIDArrayID ClearConfigurationWithDataLossController LicenseKey, DeleteLicenseKeySSPState SurfaceScanDelayArray category RebuildPriority, ExpandPriorityLogicalDrive Logical Drive categoryOnlineSpare DriveArrayAccelerator SizeSectors StripeSizeHostMode Error reportingSSPAdaptersWithAccess ConnectionNameACU scripting error messages 0-9, !, @, #, *, , , ,, -, , +, , ., /, and space. The ID Current configuration Running the CLI Using the Command Line InterfaceOverview of the ACU CLI Target variable Command variableCLI syntax Keyword abbreviationsQuerying a device Typical proceduresExample command Hiding warning promptsSyntax Sample scenarioExample Example commandsModifying the controller chassis name Sample scenario Using Selective Storage PresentationManaging host modes connection profiles Modifying connection namesExtending a logical drive Deleting target devicesIdentifying devices Expanding an arrayTarget modify size=#max? forced Target modify raid=01+0156adg? ss=8163264128256default?Managing spare drives Migrating a logical driveChanging 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 Typical scenario Setting the targetEnabling or disabling the array accelerator Disabling a redundant controller= rescan Rescanning the system Factors involved in logical drive failure Probability of logical drive failureProbability of logical drive failure Drive arrays Drive arrays and fault-tolerance methodsDrive arrays and fault-tolerance methods Hardware-based fault-tolerance methods Fault-tolerance methodsDisadvantages RAID 0-No fault toleranceAdvantages RAID 1+0-drive mirroring RAID 6 ADG-Advanced Data Guarding RAID 5-distributed data guardingRAID RAID 6 ADG Comparing the hardware-based RAID methodsSelecting a RAID method Alternative fault-tolerance methodsPost messages Diagnosing array problemsDiagnostic tools Server DiagnosticsAcronyms and abbreviations SSP Index Index