User Guide

Controller Configuration Options	Default
Drives Write Cache1	Disabled
Runtime BIOS	Enabled
Automatic Failover	Enabled
NVRAM State2	Clean
SCSI Bus Interface Definitions	Default
Controller SCSI Bus ID	7
SCSI Parity Checking	Enabled
Controller SCSI Bus Termination	Auto Mode
Additional Options	Default
SCSI Device Configuration
Initiate Sync Negotiation	Yes
Maximum Transfer Rate	160 MBytes/sec
Enable Disconnection	Yes
Initiate Wide Negotiation3	Yes
Domain Validation	Enabled

1 This option is used to control the cache on the drive, not the PERC 2. We recommend that the drive write cache remain disabled for maximum data protection. 2 This option is available only for controllers that have a battery. 3 This option is available only if Wide SCSI is supported on the attached drives.

If you want to view or change the current settings, see Starting the SCSISelect Utility. For detailed descriptions of each setting, see Using the Controller Configuration Utility.

Starting the SCSISelect Utility

To start SCSISelect, follow these steps:

1. Press Ctrl-A when the following prompt appears when you turn on or reboot your server:

    Press <Ctrl><A> for Configuration Utility!
   

2. If multiple controllers are installed, select the controller you want to configure and press Enter.
3. Select SCSISelect Utility from the menu.

The menu Controller Configuration and SCSI Configuration options are displayed.

Using SCSISelect Menus

To select a SCSISelect menu option, move the cursor to the option with the and keys, then press Enter. In some cases, selecting an option displays another menu. You can return to the previous menu at any time by pressing Esc.

To restore the original SCSISelect default values, press F6 from the Configure/View Host Adapter Settings screen.

To toggle the display between color and monochrome modes, press F5 from the main SCSISelect screen (note, however, that this feature does not work on some monitors).

Exiting SCSISelect

To exit SCSISelect, press Esc until a message prompts you to exit (if you changed any host adapter settings, you are prompted to save the changes before you exit). Select Yes to exit and reboot the system. Any changes you made in SCSISelect take effect after the server boots.

Using the Controller Configuration Utility

To access the Controller Configuration Utility, select the Controller Configuration option from the menu that appears after starting SCSISelect.

The following settings are the controller settings most likely to require any modification.

• Drives Write Cache — This option allows you to enable or disable the write-back cache feature of all SCSI disk drives connected to the controller. If Disabled, the controller will disable the write-back cache of all attached drives. If Enabled, then the controller will enable the write-back cache of all attached drives. If Drive Default, then the controller will not change the write-back cache setting of any attached drives. The default is Disabled.

  Caution: Disk drives with write-back cache enabled do not have the benefit of battery protection and could lose or corrupt data as a result of unexpected power loss or drive removal.

  Note: Certain controllers may not support drives write cache. In those cases where drives write cache is not supported, setting the option to Enabled has no effect.

• Runtime BIOS — This option enables or disables the PERC 2 runtime BIOS. The BIOS must be enabled if you want to boot from a SCSI hard disk drive connected to the PERC 2. The default is Enabled.
• Automatic Failover — If Enabled, this option allows the user to replace a failed drive in the same enclosure slot in a RAID-5, RAID 0/1, or Mirror set. The BIOS then recognizes that the failed drive has been replaced, initializes the new disk, and immediately initiates a failover. The default is Enabled. Note that this option is only supported for disks in SAF-TE enclosures or backplanes.
• NVRAM State — This option displays the current status of the NVRAM cache. This option is available only for controllers that have a battery and is for display only; it cannot be set by the user. The default is Clean.

Using the SCSI Configuration Utility

To access the SCSI Configuration Utility, select the SCSI Configuration option from the menu that appears after starting SCSISelect. Select the bus you want to configure and press Enter.

SCSI Bus Interface Options

The following settings are the SCSISelect settings most likely to require any modification.

• Controller SCSI Bus ID — This option sets the PERC 2's SCSI ID. We recommend that you leave the PERC 2 set to SCSI ID 7, which gives the PERC 2 the highest priority on the SCSI bus.
• SCSI Parity Checking —This option determines whether the PERC 2 verifies the accuracy of data transfer on the SCSI bus. You should disable SCSI Parity Checking on the PERC 2 and all SCSI devices if any SCSI device supported by the PERC 2 does not support SCSI parity; otherwise, leave it enabled. Most SCSI devices do support SCSI parity. If you are not sure whether a device supports SCSI parity, consult the documentation for the device. All Dell server disks support parity.
• Controller SCSI Bus Termination —This option sets termination on the controller card. We recommend that you leave the PERC 2 set to its default setting of Auto Mode.
• SCSI Device Configuration — For information about these options, see the next section, SCSI Device Configuration Options.
• Domain Validation — This option uses a sequence of I/O commands to determine the optimum transfer rate between the PERC 2 controller and the SCSI devices on initial boot. In the same way that a modem steps down the transfer rate based on a telephone line quality to ensure data integrity, Domain Validation limits the bandwidth to a device to guarantee reliable data transfers. The default is Enabled.

SCSI Device Configuration Options

The SCSI device settings allow you to configure certain parameters for each device on the SCSI bus. To configure settings for a specific device, you must know the SCSI ID assigned to that device. If you are not sure of the SCSI ID, see Using the Disk Utilities.

• Initiate Sync Negotiation —This option determines whether synchronous data transfer negotiation (Sync Negotiation) between the device and SCSI bus is initiated by the SCSI bus. Normally, you should leave Initiate Sync Negotiation set to Enabled, because most SCSI devices support synchronous negotiation and because it allows for faster data transfer.
• Maximum Transfer Rate —This option determines the maximum data transfer rate that the SCSI bus supports. The maximum effective data transfer rate is doubled when Initiate Wide Negotiation is set to Yes and 16-bit devices are attached (Initiate Wide Negotiation has no effect with 8-bit devices).
• Enable Disconnection —This option determines whether the SCSI bus allows the SCSI device to disconnect from the SCSI bus (sometimes called Disconnect/Reconnect or Reselection). This option should be enabled for maximum performance.
• Initiate Wide Negotiation —This option determines whether the SCSI bus attempts 16-bit data transfer instead of 8-bit data transfer. The effective data transfer rate is doubled when 16-bit data transfer is used.

Using the Disk Utilities

To access the disk utilities, select the Disk Utilities option from the main menu that appears after entering the Configuration Utility and selecting the desired PERC 2 controller. Select the desired bus and press Enter. Once the option is selected, a list of all SCSI IDs and the devices assigned to each ID is displayed.

When you select a specific ID and device, a small menu appears, displaying the options Format Disk and Verify Disk Media.

• Format Disk—This utility allows you to perform a low-level format on a hard disk drive. Each hard disk drive must be low-level formatted before you can use your operating system's partitioning and file preparation utilities, such as MS-DOS Fdisk and Format.

  Most SCSI disk devices are preformatted at the factory and do not need to be formatted again. The Format Disk utility is compatible with the vast majority of SCSI disk drives.

  Caution: A low-level format destroys all data on the drive. Be sure to back up your data before performing this operation. You cannot abort a low-level format once it is started.

  Note: The controller should not be powered-off or rebooted during a disk format. Doing so may render the disk unusable until the format is manually restarted and completed.

• Verify Disk Media —This utility allows you to scan the media of a hard disk drive for defects. If the utility finds bad blocks on the media, it prompts you to reassign them; if you select yes, the recoverable defects are remapped and those blocks are no longer used. You can press Esc at any time to abort the utility.