Promise Technology M200f, M200i, M200p, M300f, M300i, M300p, M500f, M500i, M500p Choosing a RAID Level

Chapter 7: Technology Background

247

Choosing a RAID Level

There are several issues to consider when choosing the RAID Level for your

VTrak disk array. The following discussion summarizes some advantages,

disadvantages, and applications for each choice.

RAID 0

Recommended Applications for RAID 0

•Image Editing

• Pre-Press Applications

• Any application requiring high bandwidth

RAID 1

Recommended Applications for RAID 1

• Accounting

•Payroll

•Financial

• Any application requiring very high availability

Advantages Disadvantages

Implements a striped disk array, the

data is broken down into blocks and

each block is written to a separate disk

drive

I/O performance is greatly improved by

spreading the I/O load across many

channels and drives

No parity calculation overhead is

involved

Not a true RAID because it is not fault-

tolerant

The failure of just one drive will result in

all data in an disk array being lost

Should not be used in mission critical

environments

Advantages Disadvantages

Simplest RAID storage subsystem

design

Can increase read performance by

processing data requests in parallel

since the same data resides on two

different drives

Very high disk overhead - uses only

50% of total capacity

Contents

Main VT Copyright Trademarks Important data protection information Notice Recommendations Contents Page Page Page Page Page Chapter 1: Introduction About This Manual Overview Architectural Description Features and Benefits Page Specifications M500f/i/p Page M300f/i/p, M200f/i/p FCC Statement Page Chapter 2: Installation Unpack the VTrak Mount VTrak M500f/i/p in a Rack Page Mount VTrak M300f/i/p or M200f/i/p in a Rack Page Install Disk Drives Page Drive Numbering Page Set Up Network Cable Connections Fibre Channel Storage Area Network. Fibre Channel Direct Attached Storage iSCSI Storage Area Network iSCSI Direct Attached Storage SCSI Direct Attached Storage Set Up Serial Cable Connections Connect the Power Page Page Chapter 3: Setup VTrak Setup with CLI or CLU CLI: Fibre Channel and SCSI Models (M500f/p, M300f/p, M200f/p) CLI: iSCSI Models (M500i, M300i, M200i) Page Page Management Port Exit the CLU CLU: iSCSI Models (M500i, M300i, M200i) Page Page iSCSI Ports Exit the CLU Install iSCSI Initiator on the Host PC Software-based iSCSI Initiator Page VTrak Setup with WebPAM PROe Log-in to WebPAM PROe Regular Connection Secure Connection Page Page Language Selection Create a Disk Array Automatic Express Page Advanced Page Page Page Page Page Additional Logical Drives Log-out of WebPAM PROe Internet Connection using WebPAM PROe Page Chapter 4: Management with WebPAM PROe VTrak Status Indicators Page Drive Status Indicators Audible Alarm Log-in/Log-out Log-in to WebPAM PROe Regular Connection Secure Connection Page Log-out of WebPAM PROe Page Header Language Selection View Item Function Storage Network Contact Us Tree Vie w Management Window Event Frame Subsystems Subsystem Subsystem Information Subsystem Settings Subsystem Events Background Activities Scheduler Page Lock Administrative Tools User Management User Information User Settings Administrator User Settings User User Event Subscription Page User Password Administrator User Password Users Create a User Delete a User User Sessions Network Management Management Port iSCSI Data Ports Fibre Channel Management Fibre Channel Node Fibre Channel Port Fibre Channel Port Settings Fibre Channel Statistics Fibre Channel SFP Fibre Channel Logged-in Devices Fibre Channel Initiators iSCSI Management iSCSI Node iSCSI Ports iSCSI Port Statistics iSCSI Sessions iSCSI iSNS iSCSI SLP iSCSI CHAP Page iSCSI Ping SCSI Management SCSI Channel Information SCSI Channel Settings SCSI Target Information Storage Services Initiators LUN Map Fibre Channel and iSCSI LUN Map SCSI Software Management Email SLP Web Server Teln et SNMP Page CIM Netsend Page Export Import Firmware Update Restore Factory Defaults Clear Statistics Shutdown and Restart Shutdown Monitor the Shutdown Restart the Subsystem Monitor the Restart Controllers Controller Controller Information Page Controller Statistics Controller Settings Enclosures Identify Enclosure Enclosure Enclosure Information Enclosure Settings FRU VPD Battery Buzzer Physical Drives Identify a Physical Drive Physical Drives Settings Physical Drive Physical Drive Information Page Physical Drive Settings Clear Physical Drive Conditions Force a Physical Drive Offline/Online Physical Drive Media Patrol Disk Arrays Create a Disk Array Automatic Create a Disk Array Express Page Create a Disk Array Advanced Delete a Disk Array Disk Array Disk Array Information Physical Drives in the Disk Array Logical Drives in the Disk Array Disk Array Status Disk Array Settings Create a Logical Drive Page Delete a Logical Drive Disk Array Migration Disk Array Rebuild Disk Array Background Activity Trans itio n Transport Logical Drives Logical Drive Status Logical Drive Logical Drive Information Logical Drive Statistics (in alphabetical order) Logical Drive Settings Logical Drive Background Activity Logical Drive Initialization Logical Drive Redundancy Check Logical Drive Synchronization Logical Drive PDM Logical Drive Check Table Logical Drive LUN Settings: iSCSI and Fibre Channel Logical Drive LUN Settings: SCSI Spare Drives Create Spare Drive Delete Spare Drive Spare Check All Spare Drives Spare Drive Spare Drive Information Spare Drive Settings Spare Check Individual Spare Drive Logical Drive Summary Page Chapter 5: Management with the CLU VTrak Status Indicators Page Drive Status Indicators Audible Alarm CLU Connection Serial Connection Telnet Connection Page Exit the CLU CLU Function Map A B C C, continued D E E, continued F G H I I, continued L L, continued M N P P, continued R S S, continued T U U, continued V W Quick Setup Subsystem Management Alias Media Patrol Lock Management System Date and Time Controller Management Controller Settings Physical Drive Coercion SMART Enclosure Management Enclosure Status Enclosure Management Power Supply Units Blowers Enclosure Settings Polling Interval Temperature Thresholds Batteries Locate Enclosure Physical Drive Management Global Physical Drive Settings Write Cache Read Ahead Cache DMA Mode Individual Physical Drive Settings Advanced Information Physical Drive Stati stics Clear Stale and PFA Conditions Force Physical Drive Offline/Online Locate Physical Drive Disk Array Management Create a Disk Array Automatic Express Advanced Delete a Disk Array Disk Array Information Disk Array Settings and Functions Media Patrol PDM Transport Migration Predictive Data Migration Trans itio n Accept Incomplete Array Locate Disk Array Create a Logical Drive Delete a Logical Drive Logical Drive Management Logical Drive Information Logical Drive Settings and Functions Write Cache Policy Read Cache Policy Initialization Locate Logical Drive Network Management Management Port Settings DHCP Manual iSCSI Port Settings Fibre Channel Management Node Ports Logged-in Devices Port Settings Port SFP Port Statistics Fibre Channel Initiators iSCSI Management Node Ports Port Statistics Sessions iSNS SLP CHAP Add a CHAP Delete a CHAP Ping SCSI Management Channel Information Channel Settings Target Information Background Activity Background Activity Settings Background Activities List Event Viewer Runtime Events NVRAM Events Additional Info and Management Spare Drive Management Create New Spare Drive Spare Drive Settings Delete Spare Drive LUN Mapping (Fibre Channel and iSCSI) Create New Initiator Delete Initiator Map a LUN to an Initiator LUN Mapping (SCSI) User Management Create New User Password User Settings: Display Name and Email Address User Settings: Privilege and Status Delete User Software Management Email SLP Webserver Teln et SNMP SNMP Trap Sinks CIM Netsend Netsend Recipients Flash through TFTP Clear Statistics Restore Factory Defaults Shutdown and Restart Shutdown over Telnet Shutdown over Serial Shutdown complete. It is now safe to power off the subsystem. Restart over Telnet Buzzer Chapter 6: Maintenance Page Firmware Update WebPAM PROe TFTP Server Your PC Restart VTrak Firmware Update CLU Restart VTrak Restart over Telnet Restart over Serial Replace Power Supply All Models Replace Cooling Unit Fan M500f/i/p Page Page Page Page Replace Cooling Unit Fan M300f/i/p and M200f/i/p Page Page Page Replace Cache Battery M500f/i/p Page Page Replace Cache Battery M300f/i/p and M200f/i/p Page Replace SEP M500f/i/p Replace SEP M300f/i/p and M200f/i/p Replace RAID Controller All Models Page Chapter 7: Technology Background Introduction to RAID RAID 0 Stripe RAID 1 Mirror RAID 1E Enhanced Mirror RAID 5 Block and Parity Stripe RAID 10 Mirror + Stripe RAID 50 Striping of Distributed Parity RAID 50 Axles Page Choosing a RAID Level RAID 0 RAID 1 RAID 1E RAID 5 RAID 10 RAID 50 Stripe Size Sector Size Cache Policy Read Cache Policy Write Cache Policy Cache Line Size Capacity Coercion Initialization Hot Spare Drive(s) Partition and Format the Logical Drive RAID Level Migration From To Increase Redundancy Capacity Performance Add Lose Ranges of Disk Array Expansion Create a New Logical Drive Current LD Size Maximum LD Expansion Size Sector Size Media Patrol Predictive Data Migration (PDM) PDM Triggers Transition Example Automatic Transition Manual Transition Chapter 8: Troubleshooting VTrak is Beeping LEDs Display Amber or Red Front Panel Page Drive Status Indicators Back of Enclosure Page Page CLU Reports a Problem WebPAM PROe Reports a Problem Page Event Notification Response Page Page Page Page Page Page Page Page Page Page Page Page Page Page Critical & Offline Disk Arrays When a Disk Drive Fails With a Hot Spare Drive Without a Hot Spare Drive Rebuild Operation Page Enclosure Problems Page Page Connection Problems SCSI Connections Termination iSCSI Connections Serial Connections Network Connections Unsaved Data in the Controller Cache Page Chapter 9: Support Frequently Asked Questions Page Contact Technical Support Technical Support Services United States Europe, Africa, Middle East Italy Germany Taiw an China Limited Warranty Disclaimer of other warranties Your Responsibilities Returning Product For Repair Page Appendix A: Useful Information Serial Connector Pinout 6789 1 2 3 4 5 SNMP MIB Files Load MIB Files Compliance Statement Index