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A5_bk0.book Page 2 Thursday, May 29, 2014 11:37 AM Notes, Cautions, and Warnings NOTE: A NOTE indicates important information that helps you make better use of your computer. CAUTION: A CAUTION indicates potential damage to hardware or loss of data if instructions are not followed. WARNING: A WARNING indicates a potential for property damage, personal injury, or death. ____________________ Copyright © 2014 Dell Inc. All rights reserved. This product is protected by U.S.
A5_bk0.book Page 1 Thursday, May 29, 2014 11:37 AM Contents 1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . Related Documentation 2 Features . 5 . . . . . . . . . . . . . . . . . . 7 . . . . . . . . . . . . . . . . . . . . . . . . . . 9 RAID Technology - Understanding Disk Arrays and Virtual Disks . . . . . . . . . . . . . . . . . . . . . . . 10 . . . . . . . . . . . . . . . 17 RAID Controller Features of the PERC S110 Adapter 3 Installing the Drivers .
A5_bk0.book Page 2 Thursday, May 29, 2014 11:37 AM 4 RAID Configuration and Management . . 23 Configuring the Controller: Using the PERC BIOS Configuration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Configuring the Controller: Using the DELL PERC S110 Configuration Utility 5 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System Startup Problems . . . . . . . . . . . . . . . . Warning Messages: Dell Inc.
A5_bk0.book Page 3 Thursday, May 29, 2014 11:37 AM 7 Appendix B . . . . . . . . . . . . . . . . . . . . . . . 57 About RAID . . . . . . . . . . . . . . . . . . . . . . . . 57 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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A5_bk0.book Page 5 Thursday, May 29, 2014 11:37 AM 1 Overview The Dell PowerEdge RAID Controller (PERC) S110 is targeted as a low-cost RAID solution for Dell PowerEdge value systems.
A5_bk0.book Page 6 Thursday, May 29, 2014 11:37 AM Memory 512MB or greater. Physical Disk At least one SATA hard disk drive (HDD) or SATA solid state drive (SSD). NOTE: The PERC S110 controller supports cabled configurations of up to four SATA HDD or four SATA SSD physical disks. • SATA-II HDD physical disks can be used with a PERC S110 adapter. • SATA-II SSD physical disks can be used with a PERC S110 adapter.
A5_bk0.book Page 7 Thursday, May 29, 2014 11:37 AM Related Documentation • For all storage controllers and PCIe SSD documentation, go to dell.com/storagecontrollermanuals. • For all Dell OpenManage documentation, go to dell.com/openmanagemanuals. • For all operating system documentation, go to dell.com/operatingsystemmanuals. • For all PowerEdge documentation, go to dell.com/poweredgemanuals. • For all PowerVault documentation, go to dell.com/powervaultmanuals.
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A5_bk0.book Page 9 Thursday, May 29, 2014 11:37 AM 2 Features The features of the Dell PowerEdge PERC S110 RAID Controller are described in this section. NOTE: Background Array Scan (BAS), Background virtual disk initialization (BGI), Consistency check (CC), and Online Capacity Expansion/Reconfigure (OCE/Reconfigure) run only on the operating system. Automatic Virtual Disk Rebuild Rebuilds a redundant virtual disk automatically when a failure is detected, if a hot spare is assigned for this capability.
A5_bk0.book Page 10 Thursday, May 29, 2014 11:37 AM RAID Technology - Understanding Disk Arrays and Virtual Disks The Dell PowerEdge PERC S110 RAID Controller allows: • SATA HDD, and/or SATA SSD physical disks to co-exist on a single controller. • Physical disks of the same type (SATA HDD, SATA SSD) but of different capacities. • Virtual disks to be at different RAID levels on the same controller, but not supported on the same group of physical disks.
A5_bk0.book Page 11 Thursday, May 29, 2014 11:37 AM Command Queuing Command queuing is a command protocol used by SATA physical disks that are supported by the PERC S110. Command queuing allows the host to issue multiple input/output requests to a disk simultaneously. The disk can then decide in which order to process the commands to achieve maximum performance.
A5_bk0.book Page 12 Thursday, May 29, 2014 11:37 AM If a physical disk in RAID 5 fails, parity data exists on the remaining physical disks, which can be used to restore the data to a new replacement physical disk configured as a hot spare. If a physical disk fails in RAID 10, the virtual disk remains functional and data is read from the surviving mirrored physical disk(s). A single disk failure in each mirrored set can be sustained, depending on how the mirrored set fails.
A5_bk0.book Page 13 Thursday, May 29, 2014 11:37 AM If a physical disk fails during system startup, the controller identifies the failed physical disk as follows: • At the PERC S110 adapter utility by highlighting the failed physical disk in a virtual disk in red. • In a brief warning at the Dell Inc. PERC S110 Controller BIOS screen, the virtual disk(s) found are Degraded and/or Failed. This alerts the user to the failed physical disk(s). • At Dell OpenManage Server Administrator Storage Management.
A5_bk0.book Page 14 Thursday, May 29, 2014 11:37 AM Physical Disk Roaming The controller supports moving a physical disk from one backplane slot or cable connection to another (on the same controller). The controller automatically recognizes the repositioned physical disk and logically places it in the proper order. WARNING: A virtual disk is lost if you perform disk roaming while an OCE/Reconfigure is running at Storage Management.
A5_bk0.book Page 15 Thursday, May 29, 2014 11:37 AM The PERC S110 adapter does not allow: • Creating a virtual disk from a mix of different type of physical disks. For example, a RAID 10 virtual disk cannot be created from two SATA-II HDD physical disks and a SATA SSD physical disk. All the physical disks must be of the same drive type (HDD or SSD). • Selecting a physical disk as a dedicated hot spare if the physical disk is a different type from the physical disk or disks.
A5_bk0.book Page 16 Thursday, May 29, 2014 11:37 AM CAUTION: The BIOS Configuration Utility () pauses, and prompts for action, for the degraded virtual disk(s), if a "pause if degraded" option is enabled in the BIOS Configuration Utility (). CAUTION: After the migration occurs, make sure that all of the physical disks have been migrated and are present in the appropriate virtual disks. Virtual Disk RAID Levels Virtual disks can be created at different RAID levels.
A5_bk0.book Page 17 Thursday, May 29, 2014 11:37 AM 3 Installing the Drivers The Dell PowerEdge PERC S110 RAID Controller requires controller drivers to operate with the supported operating systems. The installation method for the PERC S110 card drivers is dependent on the type of system that you have and the type of Microsoft Windows operating system that is installed in the system.
A5_bk0.book Page 18 Thursday, May 29, 2014 11:37 AM NOTE: This step is also applicable for the Dell PowerEdge R220 systems that support Microsoft Windows Server 2012, Microsoft Windows Server 2012 R2, and Microsoft Windows Server 2008 R2 SP1 operating systems. Pre-Installation Requirements for the Controller Drivers • Make sure that your system has the latest BIOS and firmware updates from the Dell Support website at dell.com/support/manuals.
A5_bk0.book Page 19 Thursday, May 29, 2014 11:37 AM Pre-Installation Procedures for the Controller Drivers Setting the SATA Controller to RAID Mode Confirm or change configuration settings at the Dell PowerEdge System window 1 Boot the system. When the Dell Power-On Self-Test (POST) screen appears, press . 2 When the Dell PowerEdge System window appears, scroll to SATA Settings and press . At the sub-screen, confirm that the SATA Controller is set to a RAID mode.
A5_bk0.book Page 20 Thursday, May 29, 2014 11:37 AM 2 Select Continue to Boot and press . 3 Proceed with "Installing the Controller Drivers During the Operating System Installation" on page 21. Change the Boot Priority List for Devices (If Applicable) To change the order of the devices (CD-ROM, optical DVD, and so on), perform the following: NOTE: If the PERC BIOS Configuration utility is open, select Continue to Boot, then press . Press to reboot the system.
A5_bk0.book Page 21 Thursday, May 29, 2014 11:37 AM Installing the Controller Drivers During the Operating System Installation CAUTION: The latest firmware, drivers and applications must be installed whenever the controller software is upgraded. A previous version of the driver might not work with the latest controller software and vice versa. 1 Reboot the system. When the POST screen appears press . 2 Insert the Windows operating system media into the optical drive of the system.
A5_bk0.book Page 22 Thursday, May 29, 2014 11:37 AM Installing bccfg3.sys Drivers Follow the procedure below to install the bccfg3.sys driver: 1 After you install the operating system on the Dell PowerEdge systems with the S110 card, navigate to the Computer Management window. 2 Select the Other Devices, right click on RAIDCORE Configuration SCSI Processor Device. A list of options are displayed. 3 Click Update Driver Software.
A5_bk0.book Page 23 Thursday, May 29, 2014 11:37 AM RAID Configuration and Management 4 The Dell PowerEdge PERC S110 RAID Controller is configured by using the PERC S110 BIOS Configuration Utility. The utility is accessed at system startup, when you are prompted to press . NOTE: To configure the PERC S110 with Dell OpenManage Server Administrator Storage Management, see the Dell Support website at dell.com/support/manuals.
A5_bk0.book Page 24 Thursday, May 29, 2014 11:37 AM • Managing Hot Spares Enables you to create or delete a global or dedicated hot spare(s). • Viewing Physical Disk Details Enables you to view detailed information about any connected physical disk. • Viewing Virtual Disk Details Enables you to view detailed information about any virtual disk. • Rescanning Disks Rescans the disks to detect new or removed physical disks or virtual disks.
A5_bk0.book Page 25 Thursday, May 29, 2014 11:37 AM The utility contains these fields: • An information field (yellow or red text): Located below the window name and the current build number. • Virtual Disks: Displays the virtual disks that have been created and information about them: virtual disk number, RAID level, virtual disk size, virtual disk status, and caching mode status. • Main Menu: Indicates the main PERC BIOS Configuration Utility operations.
A5_bk0.book Page 26 Thursday, May 29, 2014 11:37 AM Initializing Physical Disks New physical disks must be converted to RAID Capable disks before they can be used. Converting a disk to a RAID Capable disk writes controller configuration information to the physical disk. Physical disks with the following statuses can be initialized: • Non-RAID — A physical disk that was configured by a non-PERC S110. • Ready — Contains no stored data but has PERC S110 configuration information.
A5_bk0.book Page 27 Thursday, May 29, 2014 11:37 AM Initialization takes 10–15 seconds per physical disk. A status indicator shows which physical disk is being initialized. When initialization is complete, the status indicator turns off, and all channels are re-scanned automatically. CAUTION: If a physical disk has a virtual disk on it, the physical disk cannot be selected for initialization. To initialize the physical disk anyway, make sure to delete the virtual disk.
A5_bk0.book Page 28 Thursday, May 29, 2014 11:37 AM Before you Begin • At any point in this procedure, return to a prior state by pressing . • A maximum of eight virtual disks can be created with the PERC BIOS Configuration Utility. NOTE: Mixing of RAID levels is not allowed on same physical disk(s). NOTE: The Create Virtual Disk operation is not selectable when there is no available capacity on the physical disks. 1 Power-up the system to start booting.
A5_bk0.book Page 29 Thursday, May 29, 2014 11:37 AM 7 Select a size for the virtual disk, depending on the available free space of the physical disks.(Virtual disk size changes are displayed at the Create Virtual Disk and User Input fields.) NOTE: The maximum size of the virtual disk is affected by the available free space of the physical disks and by the RAID level that you select. 8 After you choose the virtual disk size, press . 9 At the User Input field, select a Caching Mode. Press .
A5_bk0.book Page 30 Thursday, May 29, 2014 11:37 AM Deleting Virtual Disks CAUTION: Although any virtual disk in the Virtual Disks field can be deleted, including the first-listed virtual disk in the field, do not delete the firstlisted virtual disk. It may be the system’s bootable virtual disk. Deleting the bootable virtual disk erases the operating system and the controller drivers.
A5_bk0.book Page 31 Thursday, May 29, 2014 11:37 AM Swapping two Virtual Disks Use the Swap Two Virtual Disks option of the PERC BIOS Configuration Utility to arrange virtual disks in a different order. CAUTION: Do not swap the first-listed virtual disk at Virtual Disks if it is the system’s bootable virtual disk. The bootable virtual disk must always be the firstlisted virtual disk at Virtual Disks.
A5_bk0.book Page 32 Thursday, May 29, 2014 11:37 AM Managing Hot Spares This option enables you to create a hot spare from a selected physical disk, or to delete a hot spare. NOTE: A hot spare can be created only if a physical disk is in Ready or Normal status at the Physical Disks field. If the physical disk is in Online status, it is being used by a virtual disk and cannot be selected as a hot spare. Create a Global Hot Spare 1 Power-up the system to start booting.
A5_bk0.book Page 33 Thursday, May 29, 2014 11:37 AM Delete a Hot Spare 1 Power-up the system to start booting. 2 When prompted, press the keys to access the PERC BIOS Configuration Utility. 3 At the Main Menu field, select Manage Hot Spare(s). Press . 4 Select Unassign Hot Spare(s). Press . 5 Use the up or down arrow key to select the physical disk(s) to delete as a hot spare(s). Press . 6 Press to delete the hot spare. 7 Press the key to confirm the action.
A5_bk0.book Page 34 Thursday, May 29, 2014 11:37 AM Viewing Virtual Disk Details 1 Power-up the system to start booting. 2 When prompted, press the keys to access the PERC BIOS Configuration Utility. 3 At the Main Menu field, select View Virtual Disk Details. Press . 4 Use the arrow keys to choose a virtual disk.
A5_bk0.book Page 35 Thursday, May 29, 2014 11:37 AM Controller Options The Controller Options feature enables you to select INT 13 boot support and select whether the boot process pauses when an error occurs. The boot process pauses when Pause if... is enabled and a virtual disk becomes Degraded or has Failed. Press to continue booting. View the error message on the window. If Pause... is OFF, the error message is displayed briefly, but the system continues to boot.
A5_bk0.book Page 36 Thursday, May 29, 2014 11:37 AM Configuring the Controller: Using the DELL PERC S110 Configuration Utility The DELL PERC S110 Configuration Utility uses a technology called UEFI Human Interface Infrastructure (HII) to allow the configuration and management of RAID controller, among other devices. The HII interface is independent of the operating system. The following sections provide information about using the DELL PERC S110 Configuration Utility.
A5_bk0.book Page 37 Thursday, May 29, 2014 11:37 AM Controller Management The Controller Management menu can be used to perform the following controller-level functions. Each of these functions is its own selectable menu option. • View Controller Information: To display information about the controller.
A5_bk0.book Page 38 Thursday, May 29, 2014 11:37 AM NOTE: If the controller does not support a feature or if the feature is supported but not applicable to specific configurations, then few virtual disk management menu options are disabled. NOTE: The help text for all of the options can be viewed by clicking Help on the top right-hand corner of the browser screen. Help text for individual option menus can also be viewed by scrolling down on each option.
A5_bk0.book Page 39 Thursday, May 29, 2014 11:37 AM 5 Troubleshooting To get help with your Dell PowerEdge PERC S110 RAID Controller, contact your Dell Technical Service representative or access the Dell Support website at dell.com/support. The chapter discusses four major categories of troubleshooting: • Normal tasks that cannot be performed during system startup • Warning messages that might appear at the Dell Inc.
A5_bk0.book Page 40 Thursday, May 29, 2014 11:37 AM 3 Scroll to Boot Sequence. Press and make sure that Hard drive C: (* PERC S110) is the first device listed. * The variable text displayed here might be: Embedded SATA 1, Slot 1, or Integrated SAS. 4 Scroll to Boot Sequence Retry. Make sure that the setting is Enabled. 5 Press to exit and continue booting. NOTE: If changes are made at the Dell Inc. PowerEdge BIOS screen, a dialog box appears and asks you to save your changes and then exit.
A5_bk0.book Page 41 Thursday, May 29, 2014 11:37 AM 2 Check Virtual Disks and determine if the bootable Non-RAID virtual disk is no longer in the first position. 3 Use the Swap Two Virtual Disks option to swap the virtual disks and place the bootable Non-RAID virtual disk in the first position of the Virtual Disks field.
A5_bk0.book Page 42 Thursday, May 29, 2014 11:37 AM To investigate the cause, check for the following: • • Whether a physical disk in the virtual disk has failed or has gone offline. Check the status at the Physical Disks field. A Degraded status depends on the RAID level of the virtual disk and the number of physical disks that have failed: – For a virtual disk at RAID 1 or RAID 5, a single physical disk failure causes a Degraded status.
A5_bk0.book Page 43 Thursday, May 29, 2014 11:37 AM • Determine if a single or multiple physical disks in a non-redundant virtual disk have failed. If yes, data is lost. Recover the lost data from a backup storage source. • Determine if two or more physical disks in a redundant virtual disk have failed. If yes, data is lost. Recover the lost data from a backup storage source.
A5_bk0.book Page 44 Thursday, May 29, 2014 11:37 AM Other Errors Appearing on the BIOS S110 does not Display Greater than Eight Virtual Disks in the BIOS Configuration Utility () Likely Cause: The function is not supported. Corrective Action: Remove all physical disks except for the last one(s) added. Then proceed with deleting the virtual disks that are not needed. Remember to take account of the virtual disks that are currently being used.
A5_bk0.book Page 45 Thursday, May 29, 2014 11:37 AM Failure Status by Virtual Disk RAID Level RAID 1, RAID 5 • Degraded: A single physical disk fails. RAID 10 • Degraded: A single physical disk fails in one or more of the mirrored sets. Volume, RAID 0 • Failed: A single physical disk fails. RAID 1 or RAID 5 • Failed: Two or more physical disks fail. RAID 10 • Failed: Two physical disks in a mirrored set fail. Use the following information as guidelines to troubleshoot the controller.
A5_bk0.book Page 46 Thursday, May 29, 2014 11:37 AM The desired physical disk is unavailable Determine whether the physical disk: • Is a dedicated hot spare and unavailable for use in another virtual disk. • Is full or has insufficient available capacity. The system already has a maximum of eight virtual disks Delete unused virtual disks. CAUTION: Deleting a virtual disk destroys all data on the virtual disk.
A5_bk0.book Page 47 Thursday, May 29, 2014 11:37 AM A Virtual Disk is in a Degraded State A physical disk was removed • Install the original physical disk, if it was inadvertently removed, or replace it with a new or used physical disk. • Initialize a new physical disk. Perform a Rescan for all physical disks that are replaced. • If the physical disk was not removed, check that its cables are correctly installed.
A5_bk0.book Page 48 Thursday, May 29, 2014 11:37 AM The designated physical disk does not have sufficient capacity to be a dedicated hot spare The capacity of the physical disk selected to be a dedicated hot spare must be equal to or larger than the capacity of the smallest physical disk in the virtual disk. For example, if the physical disk selected for a dedicated hot spare is 160 GB, and the physical disks in the virtual disk are 80 GB, 160 GB, and 500 GB, a dedicated hot spare can be assigned.
A5_bk0.book Page 49 Thursday, May 29, 2014 11:37 AM At the PERC BIOS Configuration Utility, select View Virtual Disk Details and press . Determine whether the physical disk that is designated as the global hot spare has a status of Failed. • Check to see if the physical disk is malfunctioning or is physically disconnected. • Select another physical disk as the global hot spare.
A5_bk0.book Page 50 Thursday, May 29, 2014 11:37 AM A Dedicated Hot Spare Fails The controller cannot communicate with the hot spare • Check that the cable from the controller to the physical disk is connected properly. • Make sure that the physical disk is still assigned as a global or dedicated hot spare. • Check if the physical disk assigned as the hot spare has failed. The dedicated spare is not visible in the PERC BIOS Configuration Utility or is offline.
A5_bk0.book Page 51 Thursday, May 29, 2014 11:37 AM Cannot Initialize a Physical Disk The physical disk cannot be initialized Check whether or not the physical disk is: • Already a member of a virtual disk. • Currently a global or dedicated hot spare. • Reporting an Offline state. Only physical disks that are Ready can be initialized. Disk Carrier LED Indicators The LED on the physical disk carrier indicates the state of each physical disk.
A5_bk0.book Page 52 Thursday, May 29, 2014 11:37 AM Fail to Create a Virtual Disk(s) or Perform Online Capacity Expansion / Reconfigure on a Virtual Disk(s) Cannot create a virtual disk on selected physical disks Check whether these physical/virtual disks were migrated from a legacy controller with mixed RAID levels. If so, creating additional virtual disk(s) on these physical disk(s) is not allowed. Cannot perform an Online Capacity Expansion on a virtual disk.
A5_bk0.book Page 53 Thursday, May 29, 2014 11:37 AM 1 Appendix A Controller Specifications This section contains information about the Dell PowerEdge PERC S110 RAID Controller specifications: • Technical specifications • Read, write, and cache policy • Physical and virtual disk tasks • Virtual disk specifications • Supported RAID levels Technical Specifications Table 1-1.
A5_bk0.book Page 54 Thursday, May 29, 2014 11:37 AM Table 1-1.
A5_bk0.book Page 55 Thursday, May 29, 2014 11:37 AM Physical Disk Tasks Table 1-3 indicates the physical disk tasks that are supported/not supported by the controllers at the PERC BIOS Configuration Utility. Table 1-3. Physical Disk Tasks Physical Disk Task Name Supported by PERC S110 adapter Blink/Unblink NOTE: Installing Open Manage Storage Only with a system that has a PERC S110 adapter and a backplane Assign and unassign hot spare Yes Services (OMSS) 7.0.0 or higher enables status LED support.
A5_bk0.book Page 56 Thursday, May 29, 2014 11:37 AM Virtual Disk Specifications Table 1-5 indicates the virtual disk specifications that apply to the PERC S110 adapter. Table 1-5.
A5_bk0.book Page 57 Thursday, May 29, 2014 11:37 AM 1 Appendix B About RAID A RAID disk array is a group of independent physical disks that provide high performance by increasing the number of drives used for saving and accessing data. A RAID disk subsystem improves I/O performance and data availability. The physical disks appear to the host system either as a single storage unit or multiple logical units. Data throughput improves because several disks are accessed simultaneously.
A5_bk0.book Page 58 Thursday, May 29, 2014 11:37 AM RAID 0 (striping) Provides the highest performance, but no data redundancy. Data in the virtual disk is striped (distributed) across two or more physical disks. RAID 0 virtual disks are useful for holding information, such as the operating system paging file, where performance is extremely important but redundancy is not. RAID 1 (mirroring) Mirrors data on one physical disk to another, to provide basic redundancy.
A5_bk0.book Page 59 Thursday, May 29, 2014 11:37 AM • Offers exceptional read performance, as well as redundancy. • Requires only one extra physical disk to offer redundancy. • For most systems with three or more physical disks this is the best choice as a RAID level. Supported RAID Levels Table 1-1 indicates the RAID levels that are supported by the PERC S110 adapter. Table 1-1.
A5_bk0.book Page 60 Thursday, May 29, 2014 11:37 AM • Hot Spare: A physical disk that is assigned as a dedicated or global hot spare. Virtual Disk States • Degraded: A physical disk in a redundant virtual disk has failed. Additional failures might result in loss of data. • Failed: One or more physical disks have failed. The virtual disk has gone offline. The virtual disk cannot restore the data.
A5_bk0.book Page 61 Thursday, May 29, 2014 11:37 AM Every time a physical disk is connected or disconnected while online, a rescan is performed. A rescan is automatically performed when Dell OpenManage Server Administrator Storage Management detects that a physical disk has been added or removed. Dedicated Hot Spares A dedicated hot spare is a backup physical disk for the redundant virtual disk to which it is assigned.
A5_bk0.book Page 62 Thursday, May 29, 2014 11:37 AM Virtual disks can typically be rebuilt by using a global spare disk, as long as the global hot spare is not already part of the virtual disk and has enough available capacity. Unlike a dedicated hot spare, a global hot spare can be assigned at anytime, even while tasks are running on virtual disks. If there is enough space available on the global hot spare, and a disk failure occurs, the rebuild process for the virtual disk starts automatically.
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A5_bk0.book Page 67 Thursday, May 29, 2014 11:37 AM Glossary A D A P T E R — An adapter enables the system to access peripheral devices by converting the protocol of one bus or interface to another. An adapter may also provide specialized function. For example, a RAID controller is a type of adapter that provides RAID functions. Adapters may reside on the system board or be an add-in card. Other examples of adapters include network and SCSI adapters.
A5_bk0.book Page 68 Thursday, May 29, 2014 11:37 AM immediately and the main memory read is aborted (or not started). If the data is not cached (a cache miss), it is fetched from main memory and saved in cache memory. C A C H I N G — The process of utilizing a high speed memory buffer, referred to as a cache, in order to speed up the overall read or write performance. This cache can be accessed at a higher speed than a disk subsystem.
A5_bk0.book Page 69 Thursday, May 29, 2014 11:37 AM F A I L E D P H YS I C A L D I S K — A physical disk that has ceased to function, that consistently functions improperly, or that is inaccessible. F A U L T TO L E R A N C E — Fault tolerance is the capability of the disk subsystem to undergo a single drive failure for the physical disks in a virtual disk without compromising data integrity and processing capability.
A5_bk0.book Page 70 Thursday, May 29, 2014 11:37 AM H O T S W A P — Replacement of a failed component while the system is running and operating normally. I N I T I A L I Z A T I O N — The process of writing zeros to the data fields of a virtual disk and, in fault tolerant RAID levels, generating the corresponding parity to put the virtual disk in a Ready state. Initialization generates parity information, so that the virtual disk is redundant.
A5_bk0.book Page 71 Thursday, May 29, 2014 11:37 AM NCQ (N A T I V E C O M M A N D Q U E U I N G ) — A command protocol for Serial ATA, that allows multiple, outstanding commands to be active on a drive at the same time. N O N -R A ID C O N F I G U R A T I O N — Non-RAID data is data that already exists on a replacement physical disk. The Non-RAID physical disk must be initialized before it can be used with the PERC S110 adapter.
A5_bk0.book Page 72 Thursday, May 29, 2014 11:37 AM performs a function. The functions include procedures you can use to configure physical disks and virtual disks. The PERC S110 BIOS Configuration Utility differs from the Dell Inc. system BIOS, which contains the BIOS settings for each Dell platform and is accessed by pressing during system startup. P H YS I C A L D I S K — A non-volatile, randomly-addressable device for storing data.
A5_bk0.book Page 73 Thursday, May 29, 2014 11:37 AM accessible to multiple hosts at the same time. SAS (S E R I A L A T T A C H E D S CSI) — SAS is a serial, point-to-point, enterprise-level device interface that leverages the proven Small Computer System Interface (SCSI) protocol set. The SAS interface provides improved performance, simplified cabling, smaller connectors, lower pin count, and lower power requirements when compared to parallel SCSI.
A5_bk0.book Page 74 Thursday, May 29, 2014 11:37 AM S T R I P I N G — Disk striping writes data across all physical disks in a virtual disk. Each stripe consists of consecutive virtual disk data addresses that are mapped in fixed-size units to each physical disk in the virtual disk using a sequential pattern. For example, if the virtual disk includes five physical disks, the stripe writes data to physical disks one through five without repeating any of the physical disks.
