Technology Background, Introduction to RAID | Meridian Data 1

Chapter 5: Technology Background

This chapter covers the following topics:

•Introduction to RAID (below)

•Choosing a RAID Level

•Choosing a Stripe Size

•Choosing a Sector Size

•Cache Policy

•LUN Affinity

•Capacity Coercion

•Initialization

•Hot Spare Drives

•Partition and Format the Logical Drive

•RAID Level Migration

•Media Patrol

•Predictive Data Migration

•Transition

Introduction to RAID

RAID (Redundant Array of Independent Disks) allows multiple hard drives to be combined together in a disk array. Then all or a portion of the disk array is formed into a logical drive. The operating system sees the logical drive as a single storage device, and treats it as such. The RAID software and/or controller handle all of the individual drives on its own. The benefits of a RAID can include:

•Higher data transfer rates for increased server performance

•Increased overall storage capacity for a single drive designation (such as, C, D, E, etc.)

•Data redundancy/fault tolerance for ensuring continuous system operation in the event of a hard drive failure

Different types of disk arrays use different organizational models and have varying benefits. The following outline breaks down the properties for each type of RAID disk array:

SECURSTOR ASTRA ES

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Meridian Data 1 manual Technology Background, Introduction to RAID

Contents

Contact Information SecurStor Astra ES Copyright This page intentionally left blank Table of Contents 105 This page intentionally left blank About This Manual Introduction to Astra ES Astra ES FC Host rear view Astra ES Overview Operational Features Subsystem and Controller FeaturesArchitectural Description Highlights Management Specifications Warranty and Support FCC StatementCE Statement This page intentionally left blank Unpacking the Astra ES Astra ES Installation Mounting Astra ES in a Rack Installing Disk Drives Drive Slot NumberingMUX Adapter Configuring a Storage Area Network Configuring Direct Attached StorageMaking Management and Data Connections Configuring Jbod expansion Serial Attached Scsi Host Configuring Cascaded Storage Astra ES front panel LED display Connecting the Power Regular Connection Logging into Astra GUISecure Connection Http//192.168.10.85 Perusing the Interface Using the HeaderSelecting a Language Using Management View Using Tree ViewLogging out of Astra GUI Viewing the Event Frame Working with Subsystems Working with the Storage Network Setting Redundancy for the Subsystem Setting an Alias for the SubsystemSetting Subsystem Date and Time Viewing Subsystem Information Clearing the Runtime Event Log Saving the Runtime Event LogViewing Nvram Events Saving Nvram Events Making Background Activity Settings Clearing Nvram EventsViewing Current Background Activities Running Media Patrol Running Background ActivitiesRunning PDM Viewing Scheduled Activities Setting the Lock Deleting a Scheduled ActivityViewing Lock Status Renewing the Lock Managing UsersReleasing the Lock Viewing User Information Making User Settings Modifying Your Own User SettingsSetting-up User Event Subscriptions Changing Your Own Password Changing Another User’s PasswordCreating a User List of User Privileges Managing the Network Connection Modifying Subsystem Management Port SettingsDeleting a User Viewing User Sessions Modifying Controller Management Port Settings Managing Fibre Channel ConnectionsViewing Fibre Channel Node Information Modifying Fibre Channel Port Settings Viewing Fibre Channel Port Settings Viewing Fibre Channel Port Statistics Port Setting InformationViewing SFP Information Clearing Statistics Viewing Fibre Channel Logged-in Devices Managing SAS ConnectionsViewing Fibre Channel Initiators Adding an Initiator Modifying SAS Port Settings Viewing SAS Port StatisticsViewing SAS Initiators Adding an Initiator Managing Storage ServicesDeleting an Initiator Viewing the LUN Map Managing Email Settings Managing Software ServicesEnabling LUN Masking Adding a LUN Map Managing SLP Settings Managing Telnet Settings Managing Web Server SettingsStarting or Restarting SLP service Stopping Web Server service Stopping Telnet service Managing Snmp SettingsStarting or Restarting Telnet service Adding Trap Sinks Stopping Snmp service Managing CIM SettingsStarting or Restarting Snmp service Stopping CIM service Exporting the User Database Managing Netsend Settings Importing a User Database Updating the Firmware Restoring Factory DefaultsClearing Statistics Click the Clear Statistics link Restarting the Subsystem Shutting Down the SubsystemManaging Controllers Viewing the Controllers Adjustable items Locating a ControllerViewing Controller Information Modifying Controller Settings Viewing Controller StatisticsUpgradable items Clearing an Orphan Watermark Managing EnclosuresViewing the Enclosures Locating an Enclosure Viewing Enclosure Information Modifying Enclosure SettingsViewing FRU VPD Information Checking the Batteries Managing Buzzer Settings Reconditioning a BatteryTesting the Buzzer Battery Notes Managing Physical Drives Modifying Global Physical Drive SettingsViewing a List of Physical Drives Identifying a Physical Drive Modifying Physical Drive Settings Viewing Physical Drive InformationViewing Physical Drive Statistics Forcing a Physical Drive Offline or Online Clearing Stale and PFA Conditions Viewing Disk Arrays Managing Disk ArraysCreating a Disk Array Creating a Disk Array Automatic Creating a Disk Array Advanced Creating a Disk Array Express Disk Array Creation Logical Drive CreationSummary Deleting a Disk Array Viewing Disk Array InformationDisk Array Operational Status Creating a Logical Drive Managing Disk Array Settings Migrating a Disk Array Deleting a Logical Drive Running Media Patrol on a Disk Array Rebuilding a Disk ArrayRunning PDM on a Disk Array Rebuilding Automatically Preparing a Disk Array for Transport Transitioning a Disk Array Viewing Information for All Logical Drives Managing Logical DrivesViewing Logical Drive Information Logical Drive Status Viewing Logical Drive Statistics Managing Logical Drive SettingsInitializing a Logical Drive Logical Drive Synchronization Viewing the Logical Drive Check Table Running Redundancy Check Managing Logical Drive LUN Settings Table DefinitionsLUN Mapping Parameters Viewing a List of Spare Drives Managing Spare DrivesLocating a Spare Drive Creating a Spare Drive Deleting Spare Drive Modifying Spare Drive Settings Securstor Astra ES Running Spare Check Working with the Logical Drive SummaryViewing a List of All Logical Drives Viewing Individual Logical Drive Information Maintenance Remove the Old Power Supply Replacing a Power SupplyInstall a New Power Supply Restarting the Subsystem Remove and Replace a Blower Replacing a Cooling Unit Blower Thumbscrews on blower Removing the cooling unit from enclosure Replacing a Cache Battery Replacing a RAID Controller Installing the new controllerDual Controller Subsystem Removing the old controller Replacing Astra ES controller Single Controller Subsystem This page intentionally left blank Introduction to RAID Technology Background RAID 0 Stripe Data Stripe Disk Driv es RAID 1 Mirror Data Mirror Disk Driv es Enhanced Data Mirrors Disk Driv es RAID 1E Enhanced Mirror Distributed Parity Data Blocks Disk Driv es RAID 5 Block and Parity Stripe RAID 6, stripes all drives with data and double parity RAID 6 Block and Double Parity Stripe RAID 10 Mirror + Stripe Data Stripe Mirror Disk Driv es RAID 50 Axles RAID 50 Striping of Distributed Parity RAID 50 Array No. of Drives No. of Axles Drives per Axle RAID 60 Axles RAID 60 Striping of Double Parity RAID 60 Array No. of Drives No. of Axles Drives per Axle Advantages Disadvantages Choosing a RAID Level RAID 1E RAID Choosing Sector Size Choosing Stripe SizeTB Limitation Logical Drive Size Sector Size LUN Affinity Cache PolicyRead Cache Policy Write Cache Policy Capacity Coercion Logical Drive SettingsDisk Array Creation Failover and Failback Initialization Hot Spare DrivesPartition and Format the Logical Drive RAID Level Migration Increase Redundancy From CapacityAdd Lose 100 Media Patrol Transition Predictive Data Migration PDM101 PDM Triggers Following is an example to explain the Transition function 102 103 Automatic TransitionManual Transition 104 LEDs Display Beep Tones105 Front Panel Front of Enclosure 106State LEDs Steady Flashing Amber Red Green Drive Status Indicators Back of Enclosure Drive Status Indicators107 State LEDs Error Dirty Cache Astra Web GUI Reports a Problem108 Controller LEDs Example of Yellow !’s and Red X’s in Tree View of Web GUI 109 Battery Events Reported Event Corrective Action BatteryEvent Notification Response Blowers Events 111Cache Events Reported Event Corrective Action Blowers Controller Events 112Disk Array Events Reported Event Corrective Action Controller Drive Interface Controller Events 113Enclosure Events Reported Event Corrective Action Drive Interface Controller Event Log Events 114Fibre Channel Events Reported Event Corrective Action Event Log 115 Host Interface Controller EventsReported Event Corrective Action Host Interface Controller 116 Logical Drive EventsReported Event Corrective Action Logical Drive 117 Media Patrol EventsReported Event Corrective Action Media Patrol 118 Online Capacity Expansion EventsReported Event Corrective Action Online Capacity Expansion 119 PDM EventsReported Event Corrective Action Reported Event Corrective Action Physical Disk 120 Physical Disk Events 121 Reported Event Corrective Action PSU Power Supply Units 122PSU Events 123 PSU Fans EventsReported Event Corrective Action PSU Fans 124 RAID Level Migration EventsReported Event Corrective Action RAID Level Migration 125 Rebuild EventsReported Event Corrective Action Rebuild Redundancy Check Events 126Resource Events Reported Event Corrective Action Redundancy Check Spare Check Events 127Spare Drives Events Smart Events 128 Stripe Level Migration EventsReported Event Corrective Action Stripe Level Migration Synchronization Events 129System Events Reported Event Corrective Action Synchronization 130 Critical & Offline Disk ArraysTransition Events Watermark Events 131 When a Physical Drive FailsWith a Hot Spare Drive Without a Hot Spare Drive Incomplete Array Physical Drive Problems132 Physical Drive Offline Physical Drive Failed 133Physical Drive Fails during Migration Physical Drive Fails during Transport Enclosure Problems 134Overheating 135 Power Supplies 136 137 138 Installing a Second Controller 139Dual Controllers and Sata Drives