Dell and UCPE-900, UCSE-900, UCSA-901, UCPA-901, UCSB-900, UCPB-900 manual Parameters description

Page 65

Stripe element size

Read policy

Write policy

Type of initialization

Hot spare configuration

NOTE: The default hard drive cache policy for a virtual disk with SAS hard drives is disabled and virtual disk with SATA hard drives is enabled. The Virtual Disk parameter cannot be changed in the BIOS Configuration Utility (<Ctrl> <R>). Use Dell OpenManage Storage Management for the hard drive cache setting operation.

The following table shows the parameters that you can configure when defining virtual disks.

Table 4. Parameters — description

Parameter

Description

 

 

RAID Level

Specifies whether the virtual disk is RAID 0, 1, 5, 6, 10, 50, or 60. The number

 

of disks, disk capacity, requirements for fault tolerance, performance, and

 

capacity should be considered when selecting the RAID level.

Stripe Element Size

Specifies the size of the segments written to each physical disk in a RAID 0, 1,

 

5, 6, 10, 50, and 60 virtual disk. You can set the stripe element size to 64 KB

 

128 KB, 256 KB, 512 KB, or 1 MB. The default and recommended stripe

 

element size is 64 KB.

 

A larger stripe element size provides better read performance if your system

 

mostly does sequential reads.

Write Policy

Specifies the controller write policy. You can set the write policy to Write-

 

Back or Write-Through.

 

In Write-Back caching, the controller sends a data transfer completion signal

 

to the host when the controller cache has received all the data in a

 

transaction.

 

NOTE: If a Battery Backup Unit (BBU) is present, the default cache setting

 

is Write-Back. If no BBU is present, the default cache policy default

 

setting is Write-Through.

 

NOTE: If Write-Back is enabled and the system is turned off and then on,

 

the controller may pause as the system flushes cache memory.

 

Controllers have a battery backup default to Write-Back caching.

 

In Write-Through caching, the controller sends a data transfer

 

completion signal to the host when the disk subsystem has received all

 

the data in a transaction.

Read Policy

Read-Ahead enables the read-ahead feature for the virtual disk. You can set

 

the parameter to Read-Ahead, No-Read-Ahead, or Adaptive-Read-Ahead.

 

The default is Adaptive-Read-Ahead.

 

Read-Ahead specifies that the controller uses Read-Ahead for the current

 

virtual disk. Read-Ahead capability allows the controller to read sequentially

 

ahead of requested data and store the additional data in the cache memory,

 

anticipating that the data is required soon.

65

Image 65
Contents Dell PowerEdge RAID Controller Perc 9 User’s Guide Page Contents Deploying the Perc card Driver installationBios Configuration Utility Security key and RAID management UEFI/HII RAID configuration utility100 Getting help Appendix RAID descriptionOverview Features of Perc H330 adapter cardFeatures of Perc H330 mini monolithic card Features of Perc H730 card Features of Perc H730/H730P mini monolithic card Features of Perc H730P adapter card Supported operating systems Features of Perc H830 adapter cardPerc H330 Perc H730 Perc H730P Perc H830 Perc card specificationsSAS Dell OpenManage Storage Management Management applications for Perc cardsComprehensive embedded management Related documentation Creating Global Hot Spares Creating Security Key Getting started with your Perc cardCreating Global Hot Spares Creating Security Key Creating virtual disks Setting up virtual disks Manage physical disks Creating Global Hot Spares Creating Security Key Page Perc 9 personality management FeaturesT10 protection information Enabling T10 PIImproved RAID 10 configuration Secure firmware updatePhysical disk power management 4KB block size disk drivesFull initialization Configured spin down delayTypes of virtual disk initialization Fast initialization Background initializationConsistency checks Configuring FastPath-capable virtual disks Using disk roamingDisk roaming FastPathMigrating virtual disks Virtual disk migrationConditions under which write-back is employed Virtual disk write cache policiesVirtual disk read cache policies Reconfiguration of virtual disks Or more Yes Removes Redundancy While increasing Capacity Smart Feature Fault tolerancePhysical disk failure detection Using persistent hot spare slotsPatrol Read Controller cache preservation Using replace member and revertible hot sparesPhysical disk hot swapping Non-RAID disks support Battery Transparent Learn CycleSelect OK Removing the Perc 9 adapter Deploying the Perc cardBattery cable connector Perc 9 card SAS cables Removing the Perc 9 mini monolithic controller Installing the Perc 9 adapterRemoving and installing the Perc 9 mini monolithic card Replacing the battery of a H730P mini monolithic cardRemoving the battery carrier Removing the battery Installing the Perc 9 mini monolithic controllerRemoving a H730P slim card Removing and installing a H730P slim card Replacing the battery of a H730P slim cardRemoving the battery Removing the Perc 9 mini blade controller Installing a H730P slim cardRemoving and installing the Perc 9 mini blade controller Replacing the tethered battery of a Perc 9 mini blade cardRemoving the battery carrier Removing the battery from the battery carrier Installing the battery into the battery carrier Replacing the battery carrier Installing the Perc 9 mini blade controllerRemoving the Perc FD33xD Card Removing and installing the Perc FD33xD card Replacing the battery of a Perc FD33xD cardInstalling the Perc FD33xD card Page Downloading drivers from the Dell support website Driver installationCreating the device driver media Windows driver installation Linux driver installation Page Exiting the Configuration Utility Bios Configuration UtilityEntering the Bios Configuration Utility Menu navigation controls For more information, see Managing dedicated hot spares Setting up virtual disksParameters description Virtual disk management Bios Configuration Utility menu optionsPage Virtual disk actions Physical disk actions Physical disk management PD MgmtController management Ctrl Mgmt RebuildController management actions Creating virtual disks Foreign configuration viewVirtual Disk Management Initializing virtual disks Selecting virtual disk parametersRunning a data consistency check Checking data consistencyPage Break mirror Managing preserved cache Break mirror in Bios configuration utilityDeleting virtual disks Managing dedicated hot sparesSetting LED blinking Clearing the configurationPhysical Disk Management Deleting disk groupsReplacing an online physical disk Creating global hot sparesRemoving global or dedicated hot spares Performing a manual rebuild of an individual physical disk Restrictions and limitationsStopping background initialization Controller Management Enabling boot supportEnabling boot support for a BIOS-enabled controller Disabling Bios stop on error Enabling Bios stop on errorEnabling auto import Disabling auto importRestoring factory default settings Entering the Uefi configuration utility UEFI/HII RAID configuration utilityExiting the Uefi configuration utility Navigating to Dell Perc 9 configuration utilityConfiguration management Converting physical disks to RAID capable disk Creating profile based virtual disksConverting physical disks to non-RAID disk Viewing disk group propertiesDeleting existing configurations on a RAID controller Managing foreign configurations on a RAID controllerRestoring factory settings for the controller Saving controller eventsSaving debug log Switching the controller to HBA modeEnabling security for the controller Viewing physical disks associated with a virtual disk Switching the controller to RAID modeViewing virtual disk properties Viewing physical disk properties Viewing battery propertiesHardware components management Viewing physical disks associated with an enclosure Security key implementation Security key management in the Bios configuration utilitySecurity key and RAID management Changing the security key Local Key Management LKMCreating a security key Securing pre-existing virtual disks Deleting a security keyCreating secured virtual disks Page Instant secure erase Bios configuration utility error messages TroubleshootingDiscovery error message Extra enclosure error messageDirty cache data error message Previous configuration of disks removed error messageMissing virtual disks error message Adapter at baseport not responding error message Bios disabled error messageDrive Configuration Changes Error Message Virtual disks partially degraded error message Virtual disks offline error messageVirtual disks degraded error message Firmware fault state error message Memory or battery problem error messageForeign configuration found error message Foreign configuration not found in ctrl R error messageInvalid SAS topology detected error message Previous configuration cleared or missing error messageConfigured disks removed or not accessible error message Degraded state of virtual disksSecurity key errors Memory errorsSecured foreign import errors Preserved Cache StatePhysical disk issues General IssuesFatal error or data corruption reported Unable to rebuild a fault tolerant virtual diskMultiple disks become inaccessible Physical disk displayed as blockedVirtual disk fails rebuild using a dedicated hot spare Virtual disk fails during rebuild using a global hot spareRebuilding a failed physical disk Physical disk takes a long time to rebuildReplace member errors Smart errorsSource disk fails during replace member operation Linux operating system errorsTarget disk fails General disk failsUefi error messages Disk Carrier LED IndicatorsUnable to register Scsi device error message Unhealthy Status of the DriversCorrective Action Summary of RAID levels Appendix RAID descriptionRAID terminology Disk stripingSpanned RAID levels Disk mirroringExample of Distributed Parity RAID Parity dataGetting help Locating your system Service TagContacting Dell Documentation feedback