Choosing a RAID Level, Advantages Disadvantages | Meridian Data 1

Choosing a RAID Level

There are several issues to consider when choosing the RAID Level for your Astra ES disk array. The following discussion summarizes some advantages, disadvantages, and applications for each choice.

RAID 0

	Advantages	Disadvantages

	Implements a striped disk array, the	Not a true RAID because it is not fault-
	data is broken down into blocks and	tolerant
	each block is written to a separate disk	The failure of just one drive will result in
	drive	all data in an disk array being lost
		all data in an disk array being lost
	I/O performance is greatly improved by	Should not be used in mission critical
	spreading the I/O load across many	environments
	channels and drives	environments
	channels and drives
	No parity calculation overhead is
	involved

Recommended Applications for RAID 0

•Image Editing

•Pre-Press Applications

•Any application requiring high bandwidth

RAID 1

Advantages	Disadvantages

Simplest RAID storage subsystem	Very high disk overhead - uses only
design	50% of total capacity
Can increase read performance by
processing data requests in parallel
since the same data resides on two
different drives

Recommended Applications for RAID 1

•Accounting

•Payroll

•Financial

•Any application requiring very high availability

92	EXCEL MERIDIAN DATA

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Meridian Data 1 manual Choosing a RAID Level, Advantages Disadvantages

Contents

SecurStor Astra ES Contact Information Copyright This page intentionally left blank Table of Contents 105 This page intentionally left blank Introduction to Astra ES About This Manual Astra ES Overview Astra ES FC Host rear view Subsystem and Controller Features Operational FeaturesArchitectural Description Highlights Specifications Management CE Statement Warranty and SupportFCC Statement This page intentionally left blank Astra ES Installation Unpacking the Astra ES Mounting Astra ES in a Rack MUX Adapter Installing Disk DrivesDrive Slot Numbering Making Management and Data Connections Configuring a Storage Area NetworkConfiguring Direct Attached Storage Configuring Jbod expansion Serial Attached Scsi Host Configuring Cascaded Storage Connecting the Power Astra ES front panel LED display Logging into Astra GUI Regular ConnectionSecure Connection Http//192.168.10.85 Selecting a Language Perusing the InterfaceUsing the Header Using Tree View Using Management ViewLogging out of Astra GUI Viewing the Event Frame Working with the Storage Network Working with Subsystems Setting an Alias for the Subsystem Setting Redundancy for the SubsystemSetting Subsystem Date and Time Viewing Subsystem Information Saving the Runtime Event Log Clearing the Runtime Event LogViewing Nvram Events Saving Nvram Events Viewing Current Background Activities Making Background Activity SettingsClearing Nvram Events Running Background Activities Running Media PatrolRunning PDM Viewing Scheduled Activities Viewing Lock Status Setting the LockDeleting a Scheduled Activity Managing Users Renewing the LockReleasing the Lock Viewing User Information Setting-up User Event Subscriptions Making User SettingsModifying Your Own User Settings Changing Another User’s Password Changing Your Own PasswordCreating a User List of User Privileges Modifying Subsystem Management Port Settings Managing the Network ConnectionDeleting a User Viewing User Sessions Viewing Fibre Channel Node Information Modifying Controller Management Port SettingsManaging Fibre Channel Connections Viewing Fibre Channel Port Settings Modifying Fibre Channel Port Settings Port Setting Information Viewing Fibre Channel Port StatisticsViewing SFP Information Clearing Statistics Managing SAS Connections Viewing Fibre Channel Logged-in DevicesViewing Fibre Channel Initiators Adding an Initiator Viewing SAS Initiators Modifying SAS Port SettingsViewing SAS Port Statistics Managing Storage Services Adding an InitiatorDeleting an Initiator Viewing the LUN Map Managing Software Services Managing Email SettingsEnabling LUN Masking Adding a LUN Map Managing SLP Settings Managing Web Server Settings Managing Telnet SettingsStarting or Restarting SLP service Stopping Web Server service Managing Snmp Settings Stopping Telnet serviceStarting or Restarting Telnet service Adding Trap Sinks Managing CIM Settings Stopping Snmp serviceStarting or Restarting Snmp service Stopping CIM service Managing Netsend Settings Exporting the User Database Importing a User Database Restoring Factory Defaults Updating the FirmwareClearing Statistics Click the Clear Statistics link Shutting Down the Subsystem Restarting the SubsystemManaging Controllers Viewing the Controllers Viewing Controller Information Adjustable itemsLocating a Controller Upgradable items Modifying Controller SettingsViewing Controller Statistics Managing Enclosures Clearing an Orphan WatermarkViewing the Enclosures Locating an Enclosure Modifying Enclosure Settings Viewing Enclosure InformationViewing FRU VPD Information Checking the Batteries Reconditioning a Battery Managing Buzzer SettingsTesting the Buzzer Battery Notes Modifying Global Physical Drive Settings Managing Physical DrivesViewing a List of Physical Drives Identifying a Physical Drive Viewing Physical Drive Statistics Modifying Physical Drive SettingsViewing Physical Drive Information Clearing Stale and PFA Conditions Forcing a Physical Drive Offline or Online Managing Disk Arrays Viewing Disk ArraysCreating a Disk Array Creating a Disk Array Automatic Creating a Disk Array Express Creating a Disk Array Advanced Summary Disk Array CreationLogical Drive Creation Disk Array Operational Status Deleting a Disk ArrayViewing Disk Array Information Managing Disk Array Settings Creating a Logical Drive Deleting a Logical Drive Migrating a Disk Array Rebuilding a Disk Array Running Media Patrol on a Disk ArrayRunning PDM on a Disk Array Rebuilding Automatically Transitioning a Disk Array Preparing a Disk Array for Transport Managing Logical Drives Viewing Information for All Logical DrivesViewing Logical Drive Information Logical Drive Status Managing Logical Drive Settings Viewing Logical Drive StatisticsInitializing a Logical Drive Logical Drive Synchronization Running Redundancy Check Viewing the Logical Drive Check Table LUN Mapping Parameters Managing Logical Drive LUN SettingsTable Definitions Managing Spare Drives Viewing a List of Spare DrivesLocating a Spare Drive Creating a Spare Drive Modifying Spare Drive Settings Deleting Spare Drive Securstor Astra ES Working with the Logical Drive Summary Running Spare CheckViewing a List of All Logical Drives Viewing Individual Logical Drive Information Maintenance Replacing a Power Supply Remove the Old Power SupplyInstall a New Power Supply Restarting the Subsystem Replacing a Cooling Unit Blower Remove and Replace a Blower Thumbscrews on blower Replacing a Cache Battery Removing the cooling unit from enclosure Installing the new controller Replacing a RAID ControllerDual Controller Subsystem Removing the old controller Single Controller Subsystem Replacing Astra ES controller This page intentionally left blank Technology Background Introduction to RAID Data Stripe Disk Driv es RAID 0 Stripe Data Mirror Disk Driv es RAID 1 Mirror RAID 1E Enhanced Mirror Enhanced Data Mirrors Disk Driv es RAID 5 Block and Parity Stripe Distributed Parity Data Blocks Disk Driv es RAID 6 Block and Double Parity Stripe RAID 6, stripes all drives with data and double parity Data Stripe Mirror Disk Driv es RAID 10 Mirror + Stripe RAID 50 Striping of Distributed Parity RAID 50 Axles RAID 50 Array No. of Drives No. of Axles Drives per Axle RAID 60 Striping of Double Parity RAID 60 Axles RAID 60 Array No. of Drives No. of Axles Drives per Axle Choosing a RAID Level Advantages Disadvantages RAID 1E RAID Choosing Stripe Size Choosing Sector SizeTB Limitation Logical Drive Size Sector Size Cache Policy LUN AffinityRead Cache Policy Write Cache Policy Logical Drive Settings Capacity CoercionDisk Array Creation Failover and Failback Partition and Format the Logical Drive InitializationHot Spare Drives Add Lose RAID Level MigrationIncrease Redundancy From Capacity Media Patrol 100 Predictive Data Migration PDM Transition101 PDM Triggers 102 Following is an example to explain the Transition function Manual Transition 103Automatic Transition 104 Beep Tones LEDs Display105 Front Panel 106 Front of EnclosureState LEDs Steady Flashing Amber Red Green Drive Status Indicators Drive Status Indicators Back of Enclosure107 State LEDs Astra Web GUI Reports a Problem Error Dirty Cache108 Controller LEDs 109 Example of Yellow !’s and Red X’s in Tree View of Web GUI Event Notification Response Battery EventsReported Event Corrective Action Battery 111 Blowers EventsCache Events Reported Event Corrective Action Blowers 112 Controller EventsDisk Array Events Reported Event Corrective Action Controller 113 Drive Interface Controller EventsEnclosure Events Reported Event Corrective Action Drive Interface Controller 114 Event Log EventsFibre Channel Events Reported Event Corrective Action Event Log Reported Event Corrective Action Host Interface Controller 115Host Interface Controller Events Reported Event Corrective Action Logical Drive 116Logical Drive Events Reported Event Corrective Action Media Patrol 117Media Patrol Events Reported Event Corrective Action Online Capacity Expansion 118Online Capacity Expansion Events Reported Event Corrective Action 119PDM Events 120 Reported Event Corrective Action Physical Disk 121 Physical Disk Events PSU Events Reported Event Corrective Action PSU Power Supply Units122 Reported Event Corrective Action PSU Fans 123PSU Fans Events Reported Event Corrective Action RAID Level Migration 124RAID Level Migration Events Reported Event Corrective Action Rebuild 125Rebuild Events 126 Redundancy Check EventsResource Events Reported Event Corrective Action Redundancy Check 127 Spare Check EventsSpare Drives Events Smart Events Reported Event Corrective Action Stripe Level Migration 128Stripe Level Migration Events 129 Synchronization EventsSystem Events Reported Event Corrective Action Synchronization Critical & Offline Disk Arrays 130Transition Events Watermark Events When a Physical Drive Fails 131With a Hot Spare Drive Without a Hot Spare Drive Physical Drive Problems Incomplete Array132 Physical Drive Offline 133 Physical Drive FailedPhysical Drive Fails during Migration Physical Drive Fails during Transport Overheating Enclosure Problems134 Power Supplies 135 136 137 138 Dual Controllers and Sata Drives Installing a Second Controller139