Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide First Edition (December 2000) Part Number 188270-001 Compaq Computer Corporation Compaq Confidential – Need to Know Required Writer: John Turner Project: Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Comments: final draft Part Number: 188270-xx1 File Name: a-frnt.
Notice © 2000 Compaq Computer Corporation COMPAQ, the Compaq logo, SmartStart, registered United States Patent and Trademark Office. SoftPaq is a trademark of Compaq Information Technologies Group, L.P. Microsoft, MS-DOS, Windows, and Windows NT are registered trademarks of Microsoft Corporation. All other product names mentioned herein may be trademarks and/or registered trademarks of their respective companies. Compaq shall not be liable for technical or editorial errors or omissions contained herein.
Contents About This Guide Text Conventions ........................................................................................................ v Symbols in Text ......................................................................................................... vi Symbols on Equipment .............................................................................................. vi Important Safety Information ....................................................................................
iv Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide System Setup continued Performance Tuning ................................................................................................ 3-7 Changing the Cache Read/Write Allocation..................................................... 3-7 Optimizing the Stripe Size................................................................................ 3-8 Changing the Fault Tolerance Mode .............................................
About This Guide This guide describes the features of RAID ADG and the installation of the RAID ADG Enabler Module onto the Smart Array 5300 controller board. Text Conventions This document uses the following conventions to distinguish elements of text: Keys Keys appear in boldface. A plus sign (+) between two keys indicates that they should be pressed simultaneously. USER INPUT User input appears in a different typeface and in uppercase. FILENAMES File names appear in uppercase italics.
vi Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Symbols in Text These symbols may be found in the text of this guide. They have the following meanings. WARNING: Text set off in this manner indicates that failure to follow directions in the warning could result in bodily harm or loss of life. CAUTION: Text set off in this manner indicates that failure to follow directions could result in damage to equipment or loss of information.
About This Guide Any surface or area of the equipment marked with these symbols indicates the presence of a hot surface or hot component. If this surface is contacted, the potential for injury exists. WARNING: To reduce the risk of injury from a hot component, allow the surface to cool before touching. Power Supplies or Systems marked with these symbols indicate the equipment is supplied by multiple sources of power.
viii Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Be sure to have the following information available before you call Compaq: ■ Technical support registration number (if applicable) ■ Product serial number (s) ■ Product model name(s) and numbers(s) ■ Applicable error messages ■ Add-on boards or hardware ■ Third-party hardware or software ■ Operating system type and revision level ■ Detailed, specific questions Compaq Website The Compaq website has information
Chapter 1 Introduction: RAID ADG RAID ADG is similar to RAID 5 in that data protection is achieved by writing parity information to the physical drives in the array. With RAID ADG, however, two sets of parity data are used (Figure 1-1). These two sets are different, and each set occupies a capacity equivalent to that of one of the constituent drives. (For further information about other RAID levels, refer to the Compaq Smart Array 5300 Controller User Guide.
1-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide The main advantages of RAID ADG are: ■ High read performance ■ High data availability – any two drives can fail without loss of critical data The only significant disadvantage is a relatively low write performance (lower than RAID 5), due to the need for two sets of parity data. The following table summarizes the most important features of the different varieties of RAID available.
Introduction: RAID ADG MOST IMPORTANT ALSO IMPORTANT SUGGESTED RAID LEVEL Cost effectiveness RAID ADG I/O performance RAID 0+1 Fault tolerance RAID ADG I/O performance RAID 5 (RAID 0 if fault tolerance is not required) Cost effectiveness RAID 5 (RAID 0 if fault tolerance is not required) Fault tolerance RAID 0+1 Fault tolerance Cost effectiveness I/O performance Figure 1-2.
Chapter 2 Installation For Advanced Data Guarding to be available as a fault-tolerance option on your system, the RAID ADG Enabler Module must be installed on the Smart Array 5300 controller in the server. Also, you will need to have at least 64 MB of read/write cache on the controller. Preliminary Steps WARNING: To reduce the risk of personal injury or damage to the equipment, consult the safety information and user documentation provided with your computer before attempting the installation.
2-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide 2. Turn off the server. 3. Turn off any peripheral devices attached to the server. 4. Unplug the AC power cord from the outlet, then from the server. 5. Disconnect any peripheral devices from the server. WARNING: To reduce the risk of personal injury from hot surfaces, allow the internal system components and hot-plug hard drives to cool before touching. 6. Remove or open the access panel. 7.
Installation Figure 2-2. Aligning the module on the controller board Installing the RAID ADG Enabler Module To install the RAID ADG Enabler Module: 1. Perform the preliminary steps described earlier in this chapter. 2. Ensure that the Array Accelerator on your Smart Array 5300 controller has at least 64 MB of read/write cache. 3. Hold the module at an angle and insert the rear end of the module into the appropriate slot 1. 1 2 a b Figure 2-3.
2-4 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide 4. Use one thumb to press the tab at the top of the rear end outward 2(a) while using the other thumb to gently press the other end of the module 2(b) into the connector and slot on the controller board. 5. Replace the Smart Array 5300 controller in the server. 6. Replace or close the access panel. 7. Reconnect peripherals and power. 8. Power on the system.
Chapter 3 System Setup When you have installed the RAID ADG Enabler Module, your array controller can be configured to use Advanced Data Guarding. The greater reliability of RAID ADG (see Appendix C) allows an array to be built with up to 56 drives, spanning all four channels of a Smart Array 5300 controller and its attached 2- to 4-channel adapter board.
3-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Configuring a New System for RAID ADG Windows NT and Windows 2000 There are three main steps to configure a new system for RAID ADG: 1. Set up an array. 2. Assign hard drives to the array. 3. Create logical drives within the array. Setting Up an Array 1. Check that you have the latest version of the configuration utility by visiting the Compaq website (www.compaq.com). Download and install the newer version if necessary.
System Setup Creating a Logical Drive within the Array 1. Select the array from the left-hand side of the main ACU screen. 2. Click the Create Logical Drive button 3. Select the RAID ADG check box on the screen that is displayed. 4. Enable the Array Accelerator. 5. Change the stripe size, if required. The default setting is 16 kB for RAID ADG, suitable for most common uses. The Stripe Size section later in this chapter discusses stripe sizes most useful for various applications. 6.
3-4 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Migrating an Existing Logical Drive to RAID ADG Windows NT and Windows 2000 If you are migrating from a logical drive that is configured for RAID 0 or RAID 5, you will need to expand the array before migrating to RAID ADG. Check that you have the latest version of the configuration utility by visiting the Compaq website (www.compaq.com). Download and install the newer version if necessary.
System Setup 3. Change the stripe size, if required. The default setting is 16 kB for RAID ADG, suitable for most common uses. The Stripe Size section later in this chapter discusses stripe sizes most useful for various applications. 4. Click the Done button. 5. Choose Save Configuration from the Controller menu. 6. Choose Exit from the Controller menu. NetWare If you are migrating from a logical drive that is configured for RAID 0 or RAID 5, you will need to expand the array before migrating to RAID ADG.
3-6 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide more hard drives will fail before the failed drive is replaced, leading to failure of the complete logical drive and consequent loss of data. This is less likely with RAID ADG than RAID 5, since RAID ADG can sustain failure of two drives. Data is rebuilt to the online spare at a rate of 10 to 20 minutes per gigabyte, depending on the priority assigned to rebuilding and the total number of drives in the array.
System Setup 9. In the Rebuild Priority section of the Controller Settings screen, select High if rebuilding data is more important than handling operating system requests; select Low if the controller should rebuild data only when it is idle. IMPORTANT: Selecting a high rebuild priority will result in reduced server performance while the rebuild is in progress. Setting the rebuild priority to Low allows normal server performance, since rebuilding only occurs when the server is idle. 10.
3-8 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide 4. Click the Settings button in the Controller section on the right side of the Main ACU screen. 5. In the Accelerator Ratio section of the Controller Settings screen that is displayed, either click a check box by one of the choices offered or enter a percentage in one of the fields. 6. Click the Done button. 7. Choose Save Configuration from the Controller menu. 8. Choose Exit from the Controller menu.
System Setup To change the stripe size, carry out the procedure described for your operating system in one of the following sections. Windows NT and Windows 2000 1. Check that you have the latest version of the configuration utility by visiting the Compaq website (www.compaq.com). Download and install the newer version if necessary. An ACU program icon will automatically be generated on the desktop. 2. Double-click the ACU icon. 3.
3-10 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Changing the Fault Tolerance Mode Performance decreases in this order: ■ RAID 0 (highest performance, but no protection against drive failure) ■ RAID 1 ■ RAID 5 ■ RAID ADG If performance is too low with your current fault tolerance method, it can be improved by migrating to a different RAID level.
Appendix A Regulatory Compliance Notices Federal Communications Commission Notice Part 15 of the Federal Communications Commission (FCC) Rules and Regulations has established Radio Frequency (RF) emission limits to provide an interference-free radio frequency spectrum. Many electronic devices, including computers, generate RF energy incidental to their intended function and are, therefore, covered by these rules.
A-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Class A Equipment This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
Regulatory Compliance Notices For questions regarding your product, contact: Compaq Computer Corporation P. O. Box 692000, Mail Stop 530113 Houston, Texas 77269-2000 or call 1-800- 652-6672 (1-800-OK COMPAQ). (For continuous quality improvement, calls may be recorded or monitored.) For questions regarding this FCC declaration, contact: Compaq Computer Corporation P. O. Box 692000, Mail Stop 510101 Houston, Texas 77269-2000 or call (281) 514-3333.
A-4 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Class B Equipment This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations. Cet appareil numérique de la classe B respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada.
Regulatory Compliance Notices Taiwanese Notice Compaq Confidential – Need to Know Required Writer: John Turner Project: Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Comments: final draft Part Number: 188270-xx1 File Name: e-appA.
Appendix B Electrostatic Discharge A discharge of static electricity from a finger or other conductor can damage printed circuit boards or other static-sensitive devices. This type of damage may reduce the life expectancy of the device. Preventing Electrostatic Damage To prevent electrostatic damage, observe the following precautions: ■ Avoid hand contact by transporting and storing parts in static-safe containers.
B-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Grounding Methods There are several methods for grounding. Use one or more of the following measures when handling or installing electrostatic-sensitive parts: ■ Use a wrist strap connected by a ground cord to a grounded workstation or the computer chassis. Wrist straps are flexible straps with a minimum of 1 megohm +/- 10 percent resistance in the ground cords.
Appendix C Reliability Data Figure C-1 shows the relative probability of logical drive failure for different RAID settings and different logical drive sizes, assuming no online spares are present. With RAID 0, the logical drive will fail if only one physical drive fails; with RAID 5, two physical drives must fail; and with RAID ADG, three hard drives must fail. The situation is more complex for RAID 0+1. The maximum number of hard drives that can fail without failure of the logical drive is n/2.
Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Total number of physical drives in array 1 1 6 11 16 21 26 31 36 41 46 0.1 51 56 RAID 0 0.01 0.001 RAID 5 . Relative likelihood of logical drive failure C-2 0.0001 1E-05 RAID 0+1 1E-06 RAID ADG 1E-07 1E-08 1E-09 1E-10 1E-11 Figure C-1.
Appendix D Additional POST Error Messages If a system fault is present when the computer is started up, Power-On SelfTest messages will display. Many of these messages are self-explanatory and suggest corrective actions. Messages unique to the use of RAID ADG are listed in the following table. Table D-1 POST Error Messages Number Message Meaning and recommended action 1754 Slot z drive array – RAID ADG drive(s) configured but ADG Enabler Module is detached or defective.
Appendix E Questions and Answers Q: What is RAID ADG? A: RAID ADG is an extension of RAID 5 that allows additional fault tolerance by using two different and independent parity schemes. Data is striped across a set of hard drives, just as with RAID 5, and the two sets of parity data are calculated and written across all the drives in the array. RAID ADG provides an extremely high fault tolerance, and can sustain two simultaneous drive failures without downtime or data loss.
E-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Q: What is the difference between RAID ADG and RAID 0+1? A: RAID ADG uses the capacity of only two hard drives for fault tolerance, regardless of the size of the RAID volume. This means a lower cost of implementation for six or more drives.
Index A D activating RAID ADG E-2 added security with online spare C-1 Array Configuration Utility assigning an online spare 3-6 changing cache read/write ratio 3-7 source 3-4 assigning an online spare 3-6 available stripe size 3-8 Avis Canadien A-3 data rebuild time 3-6 Declaration of Conformity A-2 default stripe size 3-8 drive failure probability graph C-1 C cabling FCC compliance A-3 cache read/write ratio 3-7 Canadian Notice A-3 capacity of online spare 3-6 CE Marking A-4 changing the stripe size
2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Reference Guide H hard drives maximum number per logical drive C-1 help additional sources vii Compaq authorized resellers, telephone numbers viii Compaq website viii technical support telephone numbers vii hot spare 3-5 I icons symbols on equipment vi Important Safety Information document vii improving performance 3-7 number of hard drives per logical drive C-1 number of hard drives supported C-1 number of online spares per ar
Index T W table available stripe size 3-8 optimum stripe size 3-8 POST error messages D-1 RAID features 1-2 Taiwanese notice A-5 technical support vii telephone numbers viii text conventions v tuning performance 3-7 warnings electrical shock vii installation 2-1 shutting down system 2-1 website, Compaq viii Compaq Confidential – Need to Know Required Writer: John Turner Project: Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Comments: final draft Part Number: 188270-xx1 File
