Dell UCSE-900, UCSA-901, UCPA-901, UCSB-900 manual Parity data, Example of Distributed Parity RAID

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Parity data

Parity data is redundant data that is generated to provide fault tolerance within certain RAID levels. In the event of a disk failure, the parity data can be used by the controller to regenerate user data. Parity data is present for RAID 5, 6, 50, and 60.

The parity data is distributed across all the physical disks in the system. If a single physical disk fails, it can be rebuilt from the parity and the data on the remaining physical disks. RAID level 5 combines distributed parity with disk striping. Parity provides redundancy for one physical disk failure without duplicating the contents of the entire physical disks.

RAID 6 combines dual distributed parity with disk striping. This level of parity allows for two disk failures without duplicating the contents of entire physical disks.

Figure 23. Example of Distributed Parity (RAID 5)

NOTE: Parity is distributed across multiple physical disks in the disk group.

Figure 24. Example of Dual Distributed Parity (RAID 6)

NOTE: Parity is distributed across all disks in the array.

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Contents Dell PowerEdge RAID Controller Perc 9 User’s Guide Page Contents Driver installation Deploying the Perc cardBios Configuration Utility UEFI/HII RAID configuration utility Security key and RAID management100 Appendix RAID description Getting helpFeatures of Perc H330 adapter card OverviewFeatures 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 Features of Perc H830 adapter card Supported operating systemsPerc card specifications Perc H330 Perc H730 Perc H730P Perc H830SAS Management applications for Perc cards Comprehensive embedded managementDell OpenManage Storage Management Related documentation Getting started with your Perc card Creating Global Hot Spares Creating Security KeyCreating Global Hot Spares Creating Security Key Creating virtual disks Setting up virtual disks Manage physical disks Creating Global Hot Spares Creating Security Key Page T10 protection information FeaturesPerc 9 personality management Enabling T10 PIPhysical disk power management Secure firmware updateImproved RAID 10 configuration 4KB block size disk drivesConfigured spin down delay Types of virtual disk initializationFull initialization Background initialization Consistency checksFast initialization Disk roaming Using disk roamingConfiguring FastPath-capable virtual disks FastPathVirtual disk migration Migrating virtual disksVirtual disk write cache policies Virtual disk read cache policiesConditions under which write-back is employed Reconfiguration of virtual disks Or more Yes Removes Redundancy While increasing Capacity Fault tolerance Smart FeatureUsing persistent hot spare slots Patrol ReadPhysical disk failure detection Using replace member and revertible hot spares Physical disk hot swappingController cache preservation Battery Transparent Learn Cycle Non-RAID disks supportSelect OK Deploying the Perc card Removing the Perc 9 adapterBattery cable connector Perc 9 card SAS cables Installing the Perc 9 adapter Removing the Perc 9 mini monolithic controllerReplacing the battery of a H730P mini monolithic card Removing and installing the Perc 9 mini monolithic cardRemoving the battery carrier Installing the Perc 9 mini monolithic controller Removing the batteryRemoving a H730P slim card Replacing the battery of a H730P slim card Removing and installing a H730P slim cardRemoving the battery Installing a H730P slim card Removing the Perc 9 mini blade controllerReplacing the tethered battery of a Perc 9 mini blade card Removing and installing the Perc 9 mini blade controllerRemoving the battery carrier Removing the battery from the battery carrier Installing the battery into the battery carrier Installing the Perc 9 mini blade controller Replacing the battery carrierRemoving the Perc FD33xD Card Replacing the battery of a Perc FD33xD card Removing and installing the Perc FD33xD cardInstalling the Perc FD33xD card Page Driver installation Creating the device driver mediaDownloading drivers from the Dell support website Windows driver installation Linux driver installation Page Bios Configuration Utility Entering the Bios Configuration UtilityExiting the Configuration Utility Menu navigation controls Setting up virtual disks For more information, see Managing dedicated hot sparesParameters description Bios Configuration Utility menu options Virtual disk managementPage Virtual disk actions Physical disk management PD Mgmt Physical disk actionsRebuild Controller management Ctrl MgmtController management actions Foreign configuration view Virtual Disk ManagementCreating virtual disks Selecting virtual disk parameters Initializing virtual disksChecking data consistency Running a data consistency checkPage Break mirror Break mirror in Bios configuration utility Managing preserved cacheManaging dedicated hot spares Deleting virtual disksPhysical Disk Management Clearing the configurationSetting LED blinking Deleting disk groupsCreating global hot spares Removing global or dedicated hot sparesReplacing an online physical disk Restrictions and limitations Stopping background initializationPerforming a manual rebuild of an individual physical disk Enabling boot support Enabling boot support for a BIOS-enabled controllerController Management Enabling auto import Enabling Bios stop on errorDisabling Bios stop on error Disabling auto importRestoring factory default settings Exiting the Uefi configuration utility UEFI/HII RAID configuration utilityEntering the Uefi configuration utility Navigating to Dell Perc 9 configuration utilityConfiguration management Converting physical disks to non-RAID disk Creating profile based virtual disksConverting physical disks to RAID capable disk Viewing disk group propertiesRestoring factory settings for the controller Managing foreign configurations on a RAID controllerDeleting existing configurations on a RAID controller Saving controller eventsSwitching the controller to HBA mode Enabling security for the controllerSaving debug log Switching the controller to RAID mode Viewing virtual disk propertiesViewing physical disks associated with a virtual disk Viewing battery properties Hardware components managementViewing physical disk properties Viewing physical disks associated with an enclosure Security key management in the Bios configuration utility Security key and RAID managementSecurity key implementation Local Key Management LKM Creating a security keyChanging the security key Deleting a security key Creating secured virtual disksSecuring pre-existing virtual disks Page Instant secure erase Discovery error message TroubleshootingBios configuration utility error messages Extra enclosure error messagePrevious configuration of disks removed error message Missing virtual disks error messageDirty cache data error message Bios disabled error message Drive Configuration Changes Error MessageAdapter at baseport not responding error message Virtual disks offline error message Virtual disks degraded error messageVirtual disks partially degraded error message Foreign configuration found error message Memory or battery problem error messageFirmware fault state error message Foreign configuration not found in ctrl R error messageConfigured disks removed or not accessible error message Previous configuration cleared or missing error messageInvalid SAS topology detected error message Degraded state of virtual disksSecured foreign import errors Memory errorsSecurity key errors Preserved Cache StateGeneral Issues Physical disk issuesMultiple disks become inaccessible Unable to rebuild a fault tolerant virtual diskFatal error or data corruption reported Physical disk displayed as blockedRebuilding a failed physical disk Virtual disk fails during rebuild using a global hot spareVirtual disk fails rebuild using a dedicated hot spare Physical disk takes a long time to rebuildSmart errors Replace member errorsTarget disk fails Linux operating system errorsSource disk fails during replace member operation General disk failsUnable to register Scsi device error message Disk Carrier LED IndicatorsUefi error messages Unhealthy Status of the Drivers Corrective Action RAID terminology Appendix RAID descriptionSummary of RAID levels Disk stripingDisk mirroring Spanned RAID levelsParity data Example of Distributed Parity RAIDContacting Dell Locating your system Service TagGetting help Documentation feedback