RAID 6 Block and Double Parity Stripe | Promise Technology EX8650

SuperTrak EX Series User Manual

RAID 6 – Block and Double Parity Stripe

RAID level 6 stores dual parity data is rotated across the physical drives along with the block data. A RAID 6 logical drive can continue to accept I/O requests when any two physical drives fail.

Figure 5. RAID 6 stripes all drives with data and dual parity

Double Distributed (P and Q) Parity

Data

Blocks

physical drives

The total capacity of a RAID 6 logical drive is the smallest physical drive times the number of physical drives, minus two.

Hence, a RAID 6 logical drive with (7) 100 GB physical drives will have a capacity of 500 GB. A RAID 6 logical drive with (4) 100 GB physical drives will have a capacity of 200 GB.

RAID 6 becomes more capacity efficient in terms of physical drives as the number of physical drives increases.

RAID 6 provides double fault tolerance. Your logical drive remains available when up to two physical drives fail.

RAID 6 is generally considered to be the safest RAID level.

A RAID 6 on SuperTrak consists of 4 to 16 physical drives.

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Image 172

Promise Technology EX8650 RAID 6 Block and Double Parity Stripe, RAID 6 stripes all drives with data and dual parity

Contents

Supertrak Copyright TrademarksImportant data protection information Recommendations Radio Frequency Interference Statement Page Contents Installing Drivers, SuperBuild Utility SuperBuild Utility, Management with WebPAM PRO, Management with WebPAM PRO, Management with WebPAM PRO, Contents Appendix a Partition and Format Appendix B Upgrades Technology Background,Support 209 Introduction About This Manual XOR Microprocessor Product OverviewHot-Swapping Operating System Support WebPAM PRO Management SoftwareBrowser Support Key Features and Benefits Advanced Hardware Design Features Benefits Compatibility Features Benefits Features Benefits SpecificationsCompatibility Installation Unpacking the SuperTrak Installing the SuperTrak Card SuperTrak EX4650 card SuperTrak EX8650 card + R G + + - + Scenario 1 Virtual Enclosure Sgpio SAS Connections and ID NumbersSuperTrak SAS Port Enclosure ID Range Drive ID Range Scenario 2 Virtual Enclosure Host PC Scenario 3 External Enclosures Daisy ChainScenario 4 External Enclosures Parallel Scenario 5 SAS Expanders Choosing the Physical Drives Level Number of Drives Creating a Logical Drive Page Installation Page Installation Installing WebPAM PRO Utility ServerAgent Operating System Support Internet Browser Browser Support Installing WebPAM PRO onto a Windows PC or Server Introduction dialog box License Agreement dialog box Setup Type dialog box Choose Destination Location dialog box SSL Security Options dialog box Ready to Install dialog box Install Complete dialog box Installing WebPAM PRO onto a Linux PC or Server License Agreement dialog box Choose Install Product dialog box Choose Install Folder dialog box WebPAM PRO Agent Configuration dialog box SSL Security Options dialog box WebPAM PRO Utility Server Configuration dialog box Register On-line dialog box Logging into WebPAM PRO Logging in at the Host PCLogging in over the Network Regular Connection Login Screen Https//192.168.10.2288443/promise Setting up WebPAM PRO Click the Add Subsystem/Host tab Add Subsystem/Host tab Installing Drivers USB Memory Stick for Windows Driver Diskette for WindowsDriver Diskette for Linux New OS Installation Windows Vista Confirming Driver Installation Existing System Windows Server Existing System Windows XP Existing System Windows Existing System Red Hat Linux Enterprise 4.4 Type cd umount /mnt/floppy SuSE Linux Enterprise SuperTrak Bios SuperBuild Utility SuperTrak Bios screen SuperTrak Bios screen, logical drive offline Main Menu SuperBuild Main Menu Controller Selection Controller Information Viewing Physical Drives Physical Drive ManagementViewing Physical Drive Information Managing Physical Drive Problems Viewing Disk Arrays Disk Array ManagementViewing Disk Array Information Creating a Disk Array Rebuilding a Disk Array Changing Disk Array SettingsDeleting a Disk Array Viewing Logical Drives Logical Drive ManagementViewing Logical Drive Information Creating a Logical Drive Write Cache Policy Choose from Write Back or Write Through Initializing a Logical Drive Changing Logical Drive Settings Deleting a Logical Drive Managing Logical Drive Problems Identifying a Critical Logical Drive Rebuilding the Logical Drive Spare Drive AvailableNo Spare Drive Available Manual Rebuild Finding the Failed Physical Drive Identifying an Offline Logical Drive RAID 1, 5, 6, 10, 50 RAID Spare Drive Management Viewing Spare DrivesViewing Spare Drive Information Creating a Spare Drive Changing Spare Drive Settings Deleting a Spare Drive Background Activity Viewing RAM Events Event LogViewing Nvram Events Clearing the Event Logs Time Sync Setting the Time ZoneSynchronizing Time with an Embedded Site Miscellaneous SAS Ready LEDsSgpio Backplane Buzzer Enabling or Disabling the Buzzer Page Management with WebPAM PRO Login Screen Management with WebPAM PRO Accessing the Interface WebPAM PRO interface Using the Header Using Tree View Using Management View WebPAM PRO Tree View Choosing a Display Language Viewing the Event Frame Deleting the Event Frame Saving the Event FrameViewing the Storage Network Logging out of WebPAM PRO Storage Network appears in Tree View Managing Users Making User SettingsViewing User Information Changing a User’s Password Making Your Own User SettingsChanging Your Own Password Deleting a User Creating a UserList of User Privileges Management with WebPAM PRO Viewing Subsystem/Host Information Working with Subsystem/Host ManagementAdding a Subsystem or Host Deleting a Subsystem or Host Setting User PrivilegeIn-Band versus Out-of-Band Page Viewing Service Status Managing Software ServicesChanging Web Server Settings Setting up Email Service Restarting the Tomcat ServerWindows Linux Setting Event Frame Refresh Time Setting up Extended SmtpSending a Test Email Message Changing CIM Client Settings Changing CIM Server Settings Setting User Rights Managing the HostViewing Host Information Refreshing the WebPAM PRO Screen Viewing Subsystem Information Managing the SubsystemClearing Statistical Data Updating the Firmware Setting an Alias for the SubsystemClick the Clear Statistics link Checking Subsystem Health Viewing the Runtime Event LogSaving the Runtime Event Log Severity Definitions Clearing the Runtime Event Log Viewing the Nvram Event Log Clearing the Nvram Event Log Saving the Nvram Event LogViewing Current Background Activities Making Background Activity Settings Running Media Patrol Running Background ActivitiesRunning PDM Viewing Scheduled Activities Scheduling an Activity 112 Viewing System Configuration Deleting a Scheduled Activity 114 Viewing Controllers Information Managing the ControllerViewing Controller Information 116 Making Controller Settings Viewing Controller Statistics Viewing Battery Information Clearing an Orphan Watermark Testing the Buzzer Making Buzzer SettingsSilencing the Buzzer Viewing Buzzer Information Managing Enclosures Viewing Enclosure Information Managing Physical Drives Viewing a List of Physical DrivesLocating a Physical Drive Virtual or Third Party Enclosures Promise Enclosures Making Global Physical Drive SettingsSata Drives SAS Drives Adjustable Items Making Physical Drive SettingsViewing Physical Drive Statistics Forcing a Physical Drive Offline or Online Clearing Stale and PFA Conditions 126 Managing Disk Arrays Locating a Disk Array 128 Creating a Disk Array Automatic Configuration Creating a Disk Array Express Configuration 131 Disk Array Creation Creating a Disk Array Advanced ConfigurationLogical Drive Creation Summary Disk Array Operational Status Making Disk Array Settings Physical Drive Status 136 137 Migrating a Disk Array Rebuilding Automatically Rebuilding Manually Running Media Patrol on a Disk Array Running PDM on a Disk Array Transitioning a Disk Array Preparing a Disk Array for Transport 142 Viewing Information for All Logical Drives Managing Logical DrivesLogical Drive Status Locating a Logical Drive Logical Drive Synchronization Viewing Logical Drive Statistics 146 Running Redundancy Check Viewing the Logical Drive Check Table 148 Managing Spare Drives Viewing a List of Spare Drives 150 Making Spare Drive Settings Deleting Spare Drive Running Spare Check Viewing a List of All Logical Drives Working with the Logical Drive SummaryViewing Individual Logical Drive Information 154 Technology Background Introduction to RAID RAID 0 Stripe RAID 0 Striping interleaves data across multiple drives RAID 1 Mirror RAID 1 Mirrors identical data to two drives RAID 1E Enhanced Mirror Enhanced Data Mirrors Physical Drives RAID 5 Block Striping with Distributed Parity RAID 5 stripes all drives with data and parity information RAID 6 Block and Double Parity Stripe RAID 6 stripes all drives with data and dual parity RAID 10 Mirror / Stripe Data Stripe Mirror Physical Drives RAID 50 Striped Distributed Parity Component Minimum Maximum RAID 50 Axles 3,3,3 RAID 60 Striping of Double Parity RAID 60 is a combination of RAID 6 and RAID RAID 60 Axles 5,5 10,10 4,4,4 167 Choosing a RAID Level Advantages Disadvantages RAID 1E 170 High Read data transaction rate Choosing Stripe Block Size Choosing Sector Size TB Limitation Choosing Cache PolicyLogical Drive Size Sector Size Read Cache Policy Capacity CoercionWrite Cache Policy Initialization Hot Spare Drives Partition and Format the Logical Drive RAID Level Migration Target Requirements None Add physical drives maximum RAID 10 must have less than 16 physical drives Physical drives maximum Ranges of Disk Array Expansion PDM Delete and Recreate Current LD Size Maximum LD Sector Size Expansion Size Predictive Data Migration PDM Media PatrolPDM Triggers Transition Drive Failure and Automatic Rebuild 186 Automatic Transition Manual Transition 188 When a Physical Drive Fails Critical & Offline Logical Drives 190 Without a Hot Spare Drive With a Hot Spare DriveRebuild Operation 192 Pre-Installation Speed, Device Types, Capacity, Cabling Frequently Asked QuestionsHow can I change the resources that the SuperTrak uses? Can I use Atapi devices on the SuperTrak EX Series? Drive IssuesWill Acpi work with HDDs on the SuperTrak EX Series? Support Post-Installation Installation Issues Capacity, BootingWhy can’t I make a dedicated spare drive in WebPAM PRO? Technical Support Services Why can’t I run WebPAM PRO in Konqueror?Contacting Technical Support United States Germany NetherlandsItaly Taiwan Limited WarrantyChina Disclaimer of other warranties Returning the Product For Repair Your Responsibilities Or retailer Appendix a Partition and Format Click the Next button to start the Wizard Appendix a Partition and Format 206 Updating SuperTrak Bios and Firmware Downloading Bios and Firmware File Downloading the WebPAM PRO Update File Installing the WebPAM PRO Update FileUpdating WebPAM PRO Logging into WebPAM PRO Appendix C Battery Backup Unit Installing the BBU SuperTrak EX Controller 212 Index Numerics 214 146 Axles 66 Capacity 18, 65, 132 List 59 150 List 73 Logical drive 65, 67, 133