Dell (PERC) S100, PERC S300 - page 23

Features

23

Consistency check

(CC)

A consistency check is a background operation that verifies

and corrects the mirror or parity data for fault-tolerant

physical disks. It is recommended that you periodically run a

consistency check on the physical disks.

By default, a consistency check corrects mirror or parity

inconsistencies. After the data is corrected, the data on the

primary physical disk in a mirror set is assumed to be the

correct data and is written to the secondary physical disk in

the mirror set.

A consistency check cannot be user-initiated in the PERC

Virtual Disk Management utility. However, a consistency

check can user-initiated when using Dell OpenManage Server

Administrator Storage Management.

Disk initialization For physical disks, initialization writes metadata to the

physical disk, so that the controller can use the physical disk.

Fault tolerance The following fault tolerance features are available with the

PERC S100 adapter and PERC S300 adapter, in order to

prevent data loss in case of a failed physical disk:

• Physical disk failure detection (automatic).

• Virtual disk rebuild using hot spares (automatic, if the hot

spare is configured for this functionality).

• Parity generation and checking (RAID 5 only).

• Hot-swap manual replacement of a physical disk without

rebooting the system (only for systems with a backplane that

allows hot-swapping).

If one side of a RAID 1 (mirror) fails, data can be rebuilt by

using the physical disk on the other side of the mirror.

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.

Table 3-1. Features of the PERC S100 controller and PERC S300 controller

(continued)

RAID Controller Feature Description

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Contents

Main Notes, Cautions, and Warnings NOTE: CAUTION: WARNING: ____________________ Contents 1 WARNING: Safety Instructions 4 Hardware Installation 3 Features 2Overview 5 Installing the Drivers 37 8 Appendix A 7 Troubleshooting 6 RAID Configuration and Management Page Page WARNING: Safety Instructions SAFETY: General SAFETY: When Working Inside Your System Protecting Against Electrostatic Discharge Page Overview Introduction General Information, Intended Audience, and Prerequisites for Use Related Documentation PERC S100 Adapter or PERC S300 Adapter Descriptions Supported Platforms Platform Requirements for the PERC S100 Controller and PERC S300 Controller Page Page About RAID Summary of RAID Levels RAID Terminology Disk Striping Disk Mirroring Spanned RAID Levels Parity Data Page Features General Features NOTE: Page Page Page Page Page Page Page Specifications Table3-2 compares the specifications of the PERC S100 adapter and PERC S300 adapter. Page Hardware Installation Before You Begin General Considerations Installing the PERC S300 Adapter Page Page Connect Physical Disks to the PERC S300 Adapter Complete the Hardware Installation Page Installing the Drivers Installing the Microsoft Windows Drivers Downloading the Controller Driver Media Pre-Installation Requirements for the Controller Drivers Page Page Page Page Page Page Performing the PERC S100 Controller or PERC S300 Controller Management Setup Procedure Page RAID Configuration and Management Configuring the Controller: Using the PERC Virtual Disk Management Utility Accessing the PERC Virtual Disk Management Utility Understanding the Text Colors in the PERC Virtual Disk Management Utility Initializing Physical Disks Creating Virtual Disks Page Deleting Virtual Disks Page Swapping Two Virtual Disks Managing Global Hot Spares Viewing Physical Disk Details Viewing Virtual Disk Details Rescanning Disks Controller Options Continuing to Boot Page Troubleshooting System Startup Problems Page Page Warning Messages: Dell Inc. PERC S100 Adapter or Dell Inc. PERC S300 Adapter BIOS Screen Page Page Page Page Page Virtual Disk-Related Errors NOTE: Use the information on the following tables as guidelines for troubleshooting the controller. Page Page Page Page Physical Disk-Related Errors Page A Appendix A Controller Specifications Read, Write, and Cache Policy Controller Tasks Physical Disk Tasks Virtual Dis k Tasks TableA-4 indicates the virtual disk tasks that are supported/not supported by the controllers. Supported RAID Levels Virtual Disk Specifications B Appendix B RAID Technology - Understanding Disk Arrays and Virtual Disks Understanding RAID Levels A PERC S100 controller or PERC S300 controller supports the following RAID levels: NOTE: Page Disk States - Virtual and Physical Disks Failure States Creating Virtual Disks: Future Expansion Understanding Physical Disks Dedicated Hot Spares Global Hot Spares C Appendix C Regulatory Notices FCC Notice (U.S. Only) FCC, Class A FCC, Class B Industry Canada Notice (Canada Only) Industry Canada, Class A Industry Canada, Class B CE Notice (European Union) Page Page D Appendix D Contacting Dell Page Index B C D E F G H I O P R S T V W warning messages Page Glossary