Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide Overview RAID Controller Features Hardware Installation Configuring the RAID Controller BIOS Configuration Utility and Dell Manager Troubleshooting Appendix A: Regulatory Notice Glossary Information in this document is subject to change without notice. © 2004 Dell Inc. All rights reserved. Reproduction in any manner whatsoever without the written permission of Dell Inc. is strictly forbidden.
Back to Contents Page Overview Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide Overview of PERC 4/SC, 4/DC, and 4e/DC Documentation Overview of PERC 4/SC, 4/DC, and 4e/DC The PERC 4 RAID controller is a high-performance, intelligent peripheral component interconnect (PCI) and PCI-Express to Small Computer System Interface (SCSI) host adapter with RAID control capabilities.
Back to Contents Page RAID Controller Features Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide Hardware Requirements RAID Controller Specifications Configuration Features Hardware Architecture Features Array Performance Features Fault Tolerance Features Operating System Software Drivers RAID Management Utilities Hardware Requirements The RAID controller can be installed in a system with a motherboard that has 5-V or 3.3-V, 32- or 64-bit PCI or PCI-Express slots.
Serial port Wide SCSI. Wide SCSI. Ultra320 and Wide SCSI. 3-pin RS232C-compatible connector (for manufacturing use only) 3-pin RS232C-compatible connector (for manufacturing use only) 3-pin RS232C-compatible connector (for manufacturing use only) NOTE: PERC 4 controller cards are not PCI Hot Pluggable. The system must be powered down in order to change or add cards. Cache Memory 64 MB of cache memory resides in a memory bank for PERC 4/SC and 128 MB for PERC 4/DC and PERC 4e/DC.
NOTE: Unlike initialization of logical drives, background initialization does not clear data from the drives. Configuration Features Table 2-3 lists the configuration features for the RAID controller. Table 2-3.
Drive roaming occurs when the hard drives are changed to different channels on the same controller. When the drives are placed on different channels, the controller detects the RAID configuration from the configuration information on the drives. Configuration data is saved in both non-volatile random access memory (NVRAM) on the RAID controller and on the hard drives attached to the controller. This maintains the integrity of the data on each drive, even if the drives have changed their target ID.
Array Performance Features Table 2-6 displays the array performance features for the RAID controller. Table 2-6. Array Performance Features Specification PERC 4/SC, PERC 4/DC, and PERC 4e/DC PCI host data transfer rate 2 - 4 GB/sec, depending on the system Drive data transfer rate Up to 320 MB/sec Maximum size of I/O requests 6.
The RAID controller firmware handles all RAID and SCSI command processing and supports the features described in Table 2-8. Table 2-8.
Back to Contents Page Hardware Installation Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide Requirements Quick Installation Procedure Installation Steps Requirements This section describes the procedures for installing the RAID controller.
Installation Steps This section provides instructions for installing the RAID controllers. Step 1 Unpack the Controller CAUTION: See your Product Information Guide for complete information about safety precautions, working inside the computer, and protecting against electrostatic discharge. Unpack and remove the controller and inspect it for damage. If the controller appears damaged, or if any items listed below are missing, contact your Dell support representative.
Table 3-1. PERC 4/SC Jumper and Connector Descriptions Connector Description Type Setting J1 Internal SCSI connector 68-pin connector Internal high-density SCSI bus connector. Connection is optional. J2 NVRAM Clear 2-pin header To CLEAR configuration data, install a jumper. J3 Serial EPROM 2-pin header To CLEAR configuration data, install a jumper. J4 Onboard BIOS Enable 2-pin header J5 SCSI Activity 2-pin header J6 Serial Port 3-pin header Connector is for diagnostic purposes.
(Dirty Cache LED) device. Optional. J4 SCSI Termination Enable Channel 1 3-pin header J5 SCSI Termination Enable Channel 0 3-pin header Jumper pins 1-2 to enable software control of SCSI termination via drive detection. Jumper pins 2-3 to disable onboard SCSI termination. J6 DIMM socket No jumper installed enables onboard SCSI termination. (See J17 and J18). This is the default.
J9 Internal SCSI Channel 0 connector 68-pin connector Internal high-density SCSI bus connector. Connection is optional. J10 Internal SCSI Channel 1 connector 68-pin connector Internal high-density SCSI bus connector. Connection is optional. J11 Mode Select 2-pin header Reserved for internal use. J12 External SCSI Channel 0 connector 68-pin connector External very-high density SCSI bus connector. Connection is optional.
Step 5 Connect SCSI Cables and SCSI Devices Connect the SCSI cables to the SCSI connectors and SCSI devices. Connect SCSI Devices Perform the following steps to connect SCSI devices. 1. Disable termination on any SCSI device that does not sit at the end of the SCSI bus. 2. Configure all SCSI devices to supply TermPWR. 3. Set proper target IDs (TIDs) for all SCSI devices. 4. The host controller has a SCSI ID of 7. 5. Connect the cable to the devices.
Step 6 Set Target IDs Set target identifiers (TIDs) on the SCSI devices. Each device in a channel must have a unique TID. Non-disk devices should have unique SCSI IDs regardless of the channel where they are connected. See the documentation for each SCSI device to set the TIDs. The RAID controller automatically occupies TID 7, which is the highest priority. The arbitration priority for a SCSI device depends on its TID. Table 3-4 lists the target IDs.
Step 8 Start the System Replace the system cover and reconnect the AC power cords. Turn power on to the host system. Set up the power supplies so that the SCSI devices are powered up at the same time as or before the host system. If the system is powered up before a SCSI device, the device might not be recognized. During bootup, the BIOS message appears: PowerEdge Expandable RAID Controller BIOS Version x.xx date Copyright (c) LSI Logic Corp. Firmware Initializing... [ Scanning SCSI Device ...(etc.)...
0x03 Serial port initialization successful 0x04 Spd (cache memory) read successful 0x05 SDRAM refresh initialization sequence successful 0x07 Start ECC initialization and memory scrub 0x08 End ECC initialization and memory scrub 0x10 SDRAM is present and properly configured. About to program ATU. 0x11 CRC check on the firmware image successful. Continue to load firmware. 0x12 Initialization of SCSI chips successful. 0x13 BIOS protocols ports initialized. About to load firmware.
Back to Contents Page Configuring the RAID Controller Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide Configuring SCSI Physical Drives Physical Device Layout Device Configuration Setting Hardware Termination Configuring Arrays Assigning RAID Levels Optimizing Storage Planning the Array Configuration This section describes how to configure for physical drives, arrays, and logical drives.
In this example, data is striped across the disks until 40 GB on Disks A, B, and C are completely full. This leaves 20 GB of disk space on Disk C. Data cannot be written to this remaining disk space, as there is no corresponding disk space available in the array to create redundant data. Physical Device Layout Use Table 4-3 to list the details for each physical device on the channels. Table 4-3.
Device type Logical drive number/drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/drive number Manufacturer/model number Firmware level Device Configuration The following
Table 4-5. Configuration for SCSI Channel 1 SCSI Channel 1 SCSI ID Device Description 0 1 2 3 4 5 6 7 Reserved for host controller. 8 9 10 11 12 13 14 15 Setting Hardware Termination NOTE: If you are using the PERC 4/DC RAID controller for clustering, then you must use hardware termination. Otherwise, software termination is OK. The SCSI bus is an electrical transmission line and must be terminated properly to minimize reflections and losses. Termination should be set at each end of the SCSI cable(s).
Hot Spares Any hard drive that is present, formatted, and initialized, but is not included in an array or logical drive, can be designated as a hot spare. A hot spare should have the same or greater capacity than the smallest physical disk in the array it protects. You can designate hard drives as hot spares using your array management software. Logical Drives Logical drives, also known as virtual disks, are arrays or spanned arrays that are available to the operating system.
Logical Drive Configuration Use Table 4-6 to list the details for each logical drive that you configure. Table 4-6.
Table 4-7. Physical Drives Required for Each RAID Level RAID Level Minimum # of Physical Drives Maximum # of Physical Drives for PERC 4/SC Maximum # of Physical Drives for PERC 4/DC and 4e/DC 0 1 14 28 1 2 2 2 5 3 14 28 10 4 14 28 50 6 14 28 Summary of RAID Levels RAID 0 uses striping to provide high data throughput, especially for large files in an environment that does not require fault tolerance.
Figure 4-2 shows the example of a RAID 50 span with three RAID 5 arrays of different sizes. (Each array can have from three to 14 hard disks.) Data is striped across the three RAID 5 arrays until the smallest array is full. The data is striped across the remaining two RAID 5 arrays until the smaller of the two arrays is full. Finally, data is stored in the additional space in the largest array. Figure 4-2.
Storage space RAID 0, RAID 5 Data redundancy RAID 5, RAID 10, RAID 50 Hard drive performance and throughput RAID 0, RAID 10 Hot spares (extra hard drives required) RAID 1, RAID 5, RAID 10, RAID 50 Back to Contents Page
Back to Contents Page BIOS Configuration Utility and Dell Manager Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide Starting the BIOS Configuration Utility Starting Dell Manager Using Dell Manager in Red Hat Linux GUI Mode Configuring Arrays and Logical Drives Designating Drives as Hot Spares Creating Arrays and Logical Drives Drive Roaming Initializing Logical Drives Deleting Logical Drives Clearing Physical Drives Rebuilding Failed Hard Drives Using a Pre-loaded SCSI Drive "A
1 Logical Drive found on the Host Adapter Adapter BIOS Disabled, No Logical Drives handled by BIOS 0 Logical Drive(s) handled by BIOS Press to Enable BIOS For each controller in the host system, the firmware version, dynamic random access memory (DRAM) size, and the status of logical drives on that controller display. After you press a key to continue, the Management Menu screen displays. NOTE: In the BIOS Configuration Utility, pressing has the same effect as pressing .
l <2> for l <3> for l <4> for l <5> for l <6> for l <7> for l <0> for Configuring Arrays and Logical Drives The following procedures apply to both the BIOS Configuration Utility and the Dell Manager for Linux. 1. Designate hot spares (optional). See Designating Drives as Hot Spares in this section for more information. 2. Select a configuration method.
The drive displays as HOTSP. 5. Save the configuration. Objects Menu 1. On the Management Menu select Objects—> Physical Drive. A physical drive selection screen appears. 2. Select a hard drive in the READY state and press to display the action menu for the drive. 3. Press the arrow keys to select Make HotSpare and press . The selected drive displays as HOTSP.
Direct I/O specifies that reads are not buffered in cache memory. Direct I/O does not override the cache policy settings. Data is transferred to cache and the host concurrently. If the same data block is read again, it comes from cache memory. Span The choices are: Yes—Array spanning is enabled for the current logical drive. The logical drive can occupy space in more than one array. No—Array spanning is disabled for the current logical drive. The logical drive can occupy space in only one array.
13. Set the Read Policy. 14. Set the Cache Policy. 15. Press to exit the Advanced Menu. 16. After you define the current logical drive, select Accept and press . The array selection screen appears if any unconfigured hard drives remain. 17. Repeat step 2 through step 16 to configure another array and logical drive. The RAID controller supports up to 40 logical drives per controller. 18. When finished configuring logical drives, press to exit Easy Configuration.
The Select Configurable Array(s) window appears. It displays the array and array number, such as A-00. 6. Press the spacebar to select the array. Span information displays in the array box. You can create multiple arrays, then select them to span them. NOTE: You can press to display the number of drives in the array, their channel and ID, and to display array information, such as the stripes, slots, and free space. 7.
Hot key information appears at the bottom of the screen. 2. Press the arrow keys to highlight specific physical drives. 3. Press the spacebar to associate the selected physical drive with the current array. The selected drive changes from READY to ONLIN A[array number]-[drive number]. For example, ONLIN A02-03 means array 2 with hard drive 3. 4. Add physical drives to the current array as desired. NOTE: Try to use drives of the same capacity in a specific array.
23. Press any key to continue, then respond to the Save prompt. 24. Initialize the logical drives you have just configured. See Initializing Logical Drives in this section for more information. Drive Roaming Drive roaming occurs when the hard drives are changed to different channels on the same controller or to different target IDs. When the drives are placed on different channels, the controller detects the RAID configuration from the configuration data on the drives.
NOTICE: The deletion of the logical drive can fail under certain conditions: During a rebuild, initialization or check consistency of a logical drive. To delete logical drives, perform the following steps: 1. Select Objects—> Logical Drive from the Management Menu. The logical drives display. 2. Use the arrow key to highlight the logical drive you want to delete. 3. Press to delete the logical drive.
Type Description Automatic Rebuild If you have configured hot spares, the RAID controller automatically tries to use them to rebuild failed disks. Select Objects—> Physical Drive to display the list of physical drives while a rebuild is in progress. The hot spare drive changes to REBLD A[array number]-[drive number], indicating the hard drive is being replaced by the hot spare. For example, REBLD A01-02 indicates that the data is being rebuilt on hard drive 2 in array 1.
The pre-loaded drive should now become an array element. 7. Press . You have now declared the pre-loaded drive as a one-disk array. 8. Set the Read Policy and Cache Policy on the Advanced Menu. 9. Exit the Advanced Menu. 10. Highlight Accept and press . Do not initialize. 11. Press and select Yes at the Save prompt. 12. Exit the configuration utility and reboot. 13. Set the host system to boot from SCSI, if such a setting is available.
A progress graph for each selected logical drive displays. 6. When the check is finished, press any key to clear the progress display. 7. Press to display the Management Menu. (To check an individual drive, select Objects—> Logical Drives from the Management Menu, the desired logical drive(s), then Check Consistency on the action menu.) NOTE: Stay at the Check Consistency menu until the check is complete.
Back to Contents Page Troubleshooting Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide General Problems BIOS Boot Error Messages Other Potential Problems Cache Migration SCSI Cable and Connector Problems Audible Warnings General Problems Table 6-1 describes general problems you might encounter, along with suggested solutions. Table 6-1. General Problems Problem The system does not boot from the RAID controller. One of the hard drives in the array fails often.
After the drive is replaced, the utility shows all drives online and all logical drives reporting optimal state. It does not allow rebuild because no failed drives are found. l Use the arrow key to select the newly inserted drive, then press . The menu for that drive displays. This occurs if you replace the drive with a drive that contains data. If the new drive is blank, this problem does not occur.
The physical drives with SCSI IDs a, b, and c are not responding on SCSI channel x. l Make sure the physical drives are properly connected and are powered on. The following SCSI IDs are not responding: Channel x:a.b.c The physical disk roaming feature did not find the physical disk with the displayed SCSI ID. No slot is available to map Following SCSI disk not found and the physical drive and the RAID controller cannot resolve the physical drives into the current configuration.
3. Transfer the cache to the new controller and connect the drives in the same order as they were connected on the previous adapter. This ensures that the configuration data on the cache matches the configuration data on they physical disks. This is important for successful cache migration. 4. Power on the system. SCSI Cable and Connector Problems If you are having problems with your SCSI cables or connectors, first check the cable connections.
Back to Contents Page Appendix A: Regulatory Notice Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide FCC Notices (U.S. Only) A Notice About Shielded Cables Class B Canadian Compliance (Industry Canada) MIC Notice (Republic of Korea Only) VCCI Class B Statement FCC Notices (U.S. Only) Most Dell systems are classified by the Federal Communications Commission (FCC) as the rating of some configurations to Class A.
l l Product name: Dell PowerEdge Expandable RAID Controller 4 Controller Company name: Dell Inc. Regulatory Department One Dell Way Round Rock, Texas 78682 USA 512-338-4400 Canadian Compliance (Industry Canada) Canadian Regulatory Information (Canada Only) This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of the Canadian Department of Communications.
Back to Contents Page
Back to Contents Page Overview Dell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide Overview of PERC 4/SC and 4/DC Documentation Overview of PERC 4/SC and 4/DC The PERC 4 RAID controller is a high-performance, intelligent peripheral component interconnect (PCI)-to-small computer system interface (SCSI) host adapter with RAID control capabilities.
Back to Contents Page RAID Controller Features Dell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide Hardware Requirements RAID Controller Specifications Configuration Features Hardware Architecture Features Array Performance Features Fault Tolerance Features Software Utilities Operating System Software Drivers RAID Management Utilities Hardware Requirements The RAID controller can be installed in a Dell™ PowerEdge™ system with a motherboard that has 5-V or 3.
Cache Memory 64 MB of cache memory resides in a memory bank for PERC 4/SC and 128 MB for PERC 4/DC. The RAID controller supports write-through or write-back caching, selectable for each logical drive. To improve performance in sequential disk accesses, the RAID controller uses read-ahead caching by default. You can disable read-ahead caching. Onboard Speaker The RAID controller has a speaker that generates audible warnings when system errors occur.
Table 2-3 lists the configuration features for the RAID controller. Table 2-3. Configuration Features Specifications PERC 4/SC RAID levels 0, 1, 5, 10, and 50 SCSI channels 1 Maximum number of drives per channel PERC 4/DC 0, 1, 5, 10, and 50 2 14 14 (for a maximum of 28 on two channels) Array interface to host PCI Rev 2.2 PCI Rev 2.
Table 2-4 lists the drive roaming features for the RAID controller. Table 2-4. Features for Drive Roaming Specification PERC 4/SC PERC 4/DC Online RAID level migration Yes Yes RAID remapping Yes Yes No reboot necessary after capacity extension Yes Yes Drive Migration Drive migration is the transfer of a set of hard drives in an existing configuration from one controller to another. The drives must remain on the same channel and be reinstalled in the same order as in the original configuration.
Table 2-7. Array Performance Features Specification PERC 4/SC and PERC 4/DC PCI host data transfer rate 532 MB/sec Drive data transfer rate Up to 320 MB/sec Maximum size of I/O requests 6.4 MB in 64 KB stripes Maximum queue tags per drive As many as the drive can accept Stripe sizes 2 KB, 4 KB, 8 KB, 16 KB, 32 KB, 64 KB, or 128 KB Maximum number of concurrent commands 255 Support for multiple initiators Only on PERC 4/DC NOTE: Using a 2 KB or 4 KB stripe size is not recommended.
l Red Hat Linux See the CERC and PERC RAID Controllers Operating System Driver Installation Guide for more information about the drivers. SCSI Firmware The RAID controller firmware handles all RAID and SCSI command processing and supports the features described in Table 2-10. Table 2-10.
Back to Contents Page Hardware Installation Dell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide Requirements Quick Installation Procedure Installation Steps Requirements This section describes the procedures for installing the RAID controller. You must have the following items to install the controller: l A PERC 4/SC or 4/DC controller l A host system with an available 32- or 64-bit, 3.
NOTICE: See the safety instructions in your system documentation for information about protecting against electrostatic discharge. Unpack and remove the controller and inspect it for damage. If the controller appears damaged, or if any items listed below are missing, contact your Dell support representative.
With jumper in = Disabled J5 SCSI Activity 2-pin header J6 Serial Port 3-pin header J7 External SCSI connector J9 SCSI bus TERMPWR Enable J10 SCSI bus Termination Enable 68-pin connector Connector for enclosure LED to indicate data transfers. Connection is optional. Connector is for diagnostic purposes. Pin-1 RXD (Receive Data) Pin-2 TXD (Transmit Data) Pin-3 GND (Ground) External very-high density SCSI bus connector. Connection is optional.
Pin-2 TXD (Transmit Data) Pin-3 GND (Ground) J16 Onboard BIOS Enable 2-pin header J17 TERMPWR Enable Channel 0 2-pin header Jumper installed enables TERMPWR from the PCI bus. Default setting. J18 TERMPWR Enable Channel 1 2-pin header No jumper installed enables TERMPWR from the SCSI bus.
4. The host controller has a SCSI ID of 7. 5. Connect the cable to the devices. NOTE: The maximum cable length for Fast SCSI (10 MB/sec) devices is 3 meters and for Ultra SCSI devices is 1.5 meters. The cable length can be up to 12 meters for LVD devices. Use shorter cables if possible. Cable Suggestions System throughput problems can occur if the SCSI cables are not the correct type.
Step 8 Start the System Replace the system cover and reconnect the AC power cords. Turn power on to the host system. Set up the power supplies so that the SCSI devices are powered up at the same time as or before the host system. If the system is powered up before a SCSI device, the device might not be recognized. During bootup, the BIOS message appears: PowerEdge Expandable RAID Controller BIOS Version x.xx date Copyright (c) Dell Inc Firmware Initializing... [ Scanning SCSI Device ...(etc.)...
The BIOS Configuration Utility prompt times out after several seconds. The host controller number, firmware version, and cache SDRAM size display in the second portion of the BIOS message. The numbering of the controllers follows the PCI slot scanning order used by the host motherboard. Light-emitting Diode (LED) Description When you start the system, the boot block and firmware perform a number of steps that load the operating system and allow the system to function properly.
Step 11 Install the Operating System Driver Operating system drivers are provided on the Dell OpenManage Systems Management CD that accompanies your PERC controller. See the CERC and PERC RAID Controllers Operating System Driver Installation Guide for additional information about installing the drivers for the operating systems. NOTE: To make sure you have the latest version of the drivers, download the updated drivers from the Dell Support web site at support.dell.com.
Back to Contents Page Configuring the RAID Controller Dell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide Configuring SCSI Physical Drives Physical Device Layout Device Configuration Setting Hardware Termination Configuring Arrays Assigning RAID Levels Optimizing Data Storage This section describes how to configure for physical drives, arrays, and logical drives. It contains tables you can complete to list the configuration for the physical drives and logical drives.
Logical drive number/ drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/ drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/drive number Manufacturer/model number Firmware level Target ID Device type Logical drive number/driv
Device type Logical drive number/drive number Manufacturer/model number Firmware level Device Configuration The following contain tables you can fill out to list the devices assigned to each channel. The PERC 4/SC controller has one channel; the PERC 4/DC has two. Use Table 4-2 to list the devices that you assign to each SCSI ID for SCSI Channel 0. Table 4-2. Configuration for SCSI Channel 0 SCSI Channel 0 SCSI ID Device Description 0 1 2 3 4 5 6 7 Reserved for host controller.
Setting Hardware Termination NOTE: If you are using the PERC 4/DC RAID controller for clustering, then you must use hardware termination. Otherwise, software termination is OK. The SCSI bus is an electrical transmission line and must be terminated properly to minimize reflections and losses. Termination should be set at each end of the SCSI cable(s). l J5 Termination Enable is a three-pin header that specifies control of the SCSI termination for channel 0.
5. Select the RAID level, cache policy, read policy, and write policy. 6. Save the configuration. 7. Initialize the system drives. 8. Install the operating system. See BIOS Configuration Utility and Dell Manager for detailed instructions. Logical Drive Configuration Use Table 4-4 to list the details for each logical drive that you configure. Table 4-4.
Assigning RAID Levels Only one RAID level can be assigned to each logical drive. Table 4-5 shows the minimum and maximum number of drives required. Table 4-5.
Optimizing Data Storage Data Access Requirements Each type of data stored in the disk subsystem has a different frequency of read and write activity. If you know the data access requirements, you can more successfully determine a strategy for optimizing the disk subsystem capacity, availability, and performance. For example, servers that support Video on Demand typically read the data often, but write data infrequently. Both the read and write operations tend to be long.
Back to Contents Page BIOS Configuration Utility and Dell Manager Dell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide Starting the BIOS Configuration Utility Starting Dell Manager Using Dell Manager in Red Hat Linux GUI Mode Configuring Arrays and Logical Drives Designating Drives as Hot Spares Creating Arrays and Logical Drives Drive Roaming Initializing Logical Drives Deleting Logical Drives Clearing Physical Drives Rebuilding Failed Hard Drives Using a Pre-loaded SCSI Drive "As-is" Fl
0 Logical Drive(s) handled by BIOS Press to Enable BIOS For each controller in the host system, the firmware version, dynamic random access memory (DRAM) size, and the status of logical drives on that controller display. After you press a key to continue, the Management Menu screen displays. NOTE: In the BIOS Configuration Utility, pressing has the same effect as pressing .
Configuring Arrays and Logical Drives 1. Designate hot spares (optional). See Designating Drives as Hot Spares in this section for more information. 2. Select a configuration method. See Creating Arrays and Logical Drives in this section for more information. 3. Create arrays using the available physical drives. 4. Define logical drives using the arrays. 5. Save the configuration information. 6. Initialize the logical drives. See Initializing Logical Drives in this section for more information.
The selected drive displays as HOTSP. Creating Arrays and Logical Drives Configure arrays and logical drives using Easy Configuration, New Configuration, or View/Add Configuration. See Using Easy Configuration, Using New Configuration, or Using View/Add Configuration for the configuration procedures. After you create an array or arrays, you can select the parameters for the logical drive. Table 5-1 contains descriptions of the parameters. Table 5-1.
In Easy Configuration, each physical array you create is associated with exactly one logical drive. You can modify the following parameters: l RAID level l Stripe size l Write policy l Read policy l Cache policy If logical drives have already been configured when you select Easy Configuration, the configuration information is not disturbed. Perform the following steps to create arrays and logical drives using Easy Configuration. 1. Select Configure—> Easy Configuration from the Management Menu.
NOTE: The PERC 4 family supports spanning across RAID 1 and 5 arrays only. 17. Repeat step 2 through step 16 to configure another array and logical drive. The RAID controller supports up to 40 logical drives per controller. 18. When finished configuring logical drives, press to exit Easy Configuration. A list of the currently configured logical drives appears. 19. Respond to the Save prompt. After you respond to the Save prompt, the Configure menu appears. 20.
NOTE: You can press to display the number of drives in the array, their channel and ID, and to display array information, such as the stripes, slots, and free space. 7. Repeat step 2 through step 6 to create another array or go to step 8 to configure a logical drive. 8. Press to configure a logical drive. The logical drive configuration screen appears. Span=Yes displays on this screen if you select two or more arrays to span.
The selected drive changes from READY to ONLIN A[array number]-[drive number]. For example, ONLIN A2-3 means array 2 with hard drive 3. 4. Add physical drives to the current array as desired. NOTE: Try to use drives of the same capacity in a specific array. If you use drives with different capacities in an array, all drives in the array are treated as if they have the capacity of the smallest drive in the array. 5. Press after you finish creating the current array.
Drive Roaming Drive roaming (also known as configuration on disk) occurs when the hard drives are changed to different channels on the same controller. When the drives are placed on different channels, the controller detects the RAID configuration from the configuration data on the drives. See Drive Roaming in the RAID Controller Features section for more information. Perform the following steps to add support for drive roaming: 1. Press during system boot to run the BIOS Configuration Utility.
NOTICE: The deletion of the logical drive can fail under certain conditions: During a rebuild, initialization or check consistency of a logical drive, if that drive has a higher logical drive number than the drive you want to delete. To delete logical drives, perform the following steps: 1. Select Objects—> Logical Drive from the Management Menu. The logical drives display. 2. Use the arrow key to highlight the logical drive you want to delete. 3. Press to delete the logical drive.
Table 5-2. Rebuild Types Type Description Automatic Rebuild If you have configured hot spares, the RAID controller automatically tries to use them to rebuild failed disks. Select Objects—> Physical Drive to display the physical drives screen while a rebuild is in progress. The drive for the hot spare drive changes to REBLD A[array number][drive number], indicating the hard drive being replaced by the hot spare.
You have now declared the pre-loaded drive as a one-disk array. 8. Set the Read Policy and Cache Policy on the Advanced Menu. 9. Exit the Advanced Menu. 10. Highlight Accept and press . Do not initialize. 11. Press and select Yes at the Save prompt. 12. Exit the configuration utility and reboot. 13. Set the host system to boot from SCSI, if such a setting is available. FlexRAID Virtual Sizing The FlexRAID Virtual Sizing option can no longer be enabled.
NOTE: Stay at the Check Consistency menu until the check is complete. Reconstructing Logical Drives A reconstruction occurs when you change the RAID level of an array or add a physical drive to an existing array. Perform the following steps to reconstruct a drive: 1. Move the arrow key to highlight Reconstruct on the Management Menu. 2. Press . The window entitled "Reconstructables" displays. This contains the logical drives that can be reconstructed.
Back to Contents Page Troubleshooting Dell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide General Problems BIOS Boot Error Messages Other Potential Problems Cache Migration SCSI Cable and Connector Problems Audible Warnings General Problems Table 6-1 describes general problems you might encounter, along with suggested solutions. Table 6-1. General Problems Problem Some operating systems do not load in a system with a RAID controller. One of the hard drives in the array fails often.
rebuild. l After the drive is replaced, the utility shows all drives online and all logical drives reporting optimal state. It does not allow rebuild because no failed drives are found. l Access the BIOS Configuration Utility and select Objects—> Physical Drive to display the list of physical drives. Use the arrow key to select the newly inserted drive, then press . The menu for that drive displays. This occurs if you replace the drive with a drive that contains data.
l Reconnect, replace, or rebuild any drive that is not responding. l Make sure the cache memory has been properly installed. Not enough memory on the adapter to support the current configuration. l Make sure the cache memory has been properly installed. The physical drives with SCSI IDs a, b, and c are not responding on SCSI channel x. l Make sure the physical drives are properly connected and are powered on.
See RAID Controller Features for information about the jumper to set to clear NVRAM. l Make sure that the configuration data on the disks is intact. l Transfer the cache to the new controller and connect the drives in the same order as they were connected on the previous adapter. This ensures that the configuration data on the cache matches the configuration data on they physical disks. This is important for successful cache migration. l Power on the system.
Back to Contents Page Appendix A: Regulatory Notice Dell™ PowerEdge™ Expandable RAID Controller 4/SC and 4/DC User's Guide FCC Notices (U.S. Only) A Notice About Shielded Cables: Class B Canadian Compliance (Industry Canada) MIC VCCI Class B Statement FCC Notices (U.S. Only) Most Dell systems are classified by the Federal Communications Commission (FCC) as the rating of some configurations to Class A.
l l Product name: Dell PowerEdge Expandable RAID Controller 4 Controller Company name: Dell Inc. Regulatory Department One Dell Way Round Rock, Texas 78682 USA 512-338-4400 Canadian Compliance (Industry Canada) Canadian Regulatory Information (Canada Only) This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of the Canadian Department of Communications.
Back to Contents Page
Back to Contents Page Glossary Dell™ PowerEdge™ Expandable RAID Controller 4/SC, 4/DC, and 4e/DC User's Guide A•C•D•F•G•H•I•L•M•O•P •R•S Array A grouping of hard drives that combines the storage space on the hard drives into a single segment of contiguous storage space. The RAID controller can group hard drives on one or more channels into an array. A hot spare drive does not participate in an array.
Disk Subsystem A collection of disks and the hardware that connects them to one or more host systems. The hardware can include an intelligent controller, or the disks can attach directly to a host system. Double Buffering A technique that achieves maximum data transfer bandwidth by constantly keeping two I/O requests for adjacent data outstanding. A software component begins a double-buffered I/O stream by issuing two requests in rapid sequence.
Multi-threaded Having multiple concurrent or pseudo-concurrent execution sequences. Used to describe processes in systems. Multi-threaded processes allow throughputintensive applications to efficiently use a disk array to increase I/O performance. Operating Environment The operating environment includes the host system where the group of hard drives is attached, any I/O buses and controllers, the host operating system, and any additional software required to operate the array.
SCSI (small computer system interface) A processor-independent standard for system-level interfacing between a system and intelligent devices, including hard disks, diskettes, CD drives, printers, scanners, etc. SCSI can connect up to seven devices to a single adapter (or host adapter) on the system's bus. SCSI transfers eight or 16 bits in parallel and can operate in either asynchronous or synchronous modes. The synchronous transfer rate is up to 320 MB/sec.
