HP Microsoft Windows Server 2003 for Itanium-based Systems Changing the surface scan delay time

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if the controller has a battery-backed cache (because only battery-backed cache can be used for write cache) and if there are logical drives configured on the controller.

Syntax:

<target> modify cr=#/#?

where <target> is a controller, and #/# is the cache ratio in the format read percentage/write

percentage.

Example command:

=> ctrl slot=3 modify cr=25/75

Changing the surface scan delay time

The setting for the surface scan delay determines the time interval for which a controller must be inactive before a surface scan analysis is started on the physical drives that are connected to it.

Surface scan analysis is an automatic background process that ensures that you can recover data if a drive failure occurs. The scanning process checks physical drives in fault-tolerant logical drives for bad sectors, and in RAID 5 or RAID 6 (ADG) configurations, it also verifies the consistency of parity data.

Syntax:

<target> modify ssd=#

where <target> is a controller and # is a number between 1 and 30. This number determines the delay time in seconds, but you do not need to include units with the command.

Example command:

=> ctrl sn=P56350D9IP903J modify ssd=3

Re-enabling a failed logical drive

If a logical drive has failed and the data on it is invalid or non-recoverable, you can re-enable the logical drive so that it can be reused. This process preserves the structure of the logical drive and merely deletes data, whereas a delete command applied to a logical drive deletes the logical drive structure as well as the data.

Syntax:

<target> modify reenable [forced]

Example command:

=> ctrl slot=3 ld 1 modify reenable forced

Enabling or disabling the drive cache

On controllers and drives that support physical drive write cache, you can use this command to enable or disable the write cache for all drives on the controller.

CAUTION: Because physical drive write cache is not battery-backed, you could lose data if a power failure occurs during a write process. To minimize this possibility, use a backup power supply.

Syntax:

<target> modify drivewritecache=enabledisable [forced]

where <target> is a controller that supports drive write cache.

Example command:

=> ctrl slot=5 modify dwc=enable

Using the Command Line Interface 53

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Contents HP Array Configuration Utility User Guide Audience assumptions Contents Diagnosing array problems Installing ACU Features and system requirementsGetting started This sectionComparison 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 Creating an array Using the configuration wizardsClick Finish Click Create an array, and then click BeginConfiguring 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 Modifying a configuration using the Configuration wizards Modifying a configuration using Express modeClear Configuration 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 Migrate a logical drive Extend logical driveClick Extend logical drive, and then click Begin Click Migrate a logical drive, and then click BeginSelective Storage Presentation Spare managementRA4x00 controllers Click Spare Management, and then click BeginMSA and Smart Array Cluster storage controllers Click ACU Switch Configuration Configuring switchesRecombining a split, mirrored array Splitting a mirrored arrayModifying an existing configuration Scripting in ACU Command line syntaxIntroduction to scripting in ACU Operating modesCpqacuxe -i Filename Sample custom input scriptDescription of option categories in ACU scripting Script file optionsController category Control categoryAction MethodController ClearConfigurationWithDataLossLicenseKey, DeleteLicenseKey RAIDArrayIDArray category SurfaceScanDelayRebuildPriority, ExpandPriority SSPStateOnlineSpare Logical Drive categoryDrive LogicalDriveSectors SizeStripeSize ArrayAcceleratorSSPAdaptersWithAccess Error reportingConnectionName HostModeACU scripting error messages 0-9, !, @, #, *, , , ,, -, , +, , ., /, and space. The ID Current configuration Running the CLI Using the Command Line InterfaceOverview of the ACU CLI CLI syntax Command variableKeyword abbreviations Target variableExample command Typical proceduresHiding warning prompts Querying a deviceSyntax Sample scenarioExample Example commandsModifying the controller chassis name Sample scenario Using Selective Storage PresentationManaging host modes connection profiles Modifying connection namesIdentifying devices Deleting target devicesExpanding an array Extending a logical driveManaging spare drives Target modify raid=01+0156adg? ss=8163264128256default?Migrating a logical drive 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 Enabling or disabling the array accelerator Setting the targetDisabling a redundant controller Typical scenario= rescan Rescanning the systemFactors 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 methodsDiagnostic tools Diagnosing array problemsServer Diagnostics Post messagesAcronyms and abbreviations SSP Index Index