Dell PowerEdge 2500SC - Manual (Page 17)

setting is Yes.
Leave Enable Disconnection set to Yes if two or more SCSI devices are connected to the host adapter. This optimizes SCSI bus performance. If only one
SCSI device is connected to the host adapter, set Enable Disconnection to No to achieve slightly better performance.
l Send Start Unit Command — Determines whether the start unit command is sent to the SCSI device during the boot routine. The default is Yes.
Setting this option to Yes reduces the load on your system's power supply by allowing the host adapter to start SCSI devices one at a time when you boot your
system. When this option is set to No, the devices are allowed to start at the same time. Most devices require you to set a jumper before they can respond to this
command.
l Enable Write Back Cache — Signals the completion of a write request as soon as the data is in cache. Actual writing to the disk occurs at a later time. The
default setting is N/C.
l BIOS Multiple LUN Support — Provides support for peripherals that contain multiple SCSI devices, such as autoloading tape drives and CD-ROM
changers.
l Include in BIOS Scan — Enables you to set whether the system BIOS scans this device during system start-up. The default is Yes.
Advanced Configuration Settings
The advanced host adapter settings should not be changed unless absolutely necessary. These values are set by Dell, and changing them may cause conflicts with the
SCSI devices.
l Reset SCSI Bus at IC Initialization — Enables the SCSI bus to be reset when the controller is initialized. The default is Enabled.
l Display <Ctrl><a> Message During BIOS Initialization — Determines whether the Press <CTRL><A> for SCSISelect (TM) Utility! message appears
on your screen during system start-up. The default setting is Enabled. If this setting is disabled, you can still run the SCSISelect utility by pressing <Ctrl><a>
after the host adapter BIOS banner appears.
l Extended BIOS Translation For DOS Drives > 1 GB — Determines whether extended translation is available for SCSI hard-disk drives with capacities
greater than 1 GB. The default setting is Enabled.
The standard translation scheme for SCSI host adapters provides a maximum accessible capacity of 1 GB. To support hard-disk drives larger than 1 GB, the
78x x series host adapters include an extended translation scheme that supports hard-disk drives as large as 8 GB, with a maximum partition size of 2 GB under
the DOS operating system.
It is not necessary to enable the Extended BIOS Translation setting if you are using another operating system, such as Novell NetWare.
When you partition a hard-disk drive larger than 1 GB, use the MS-DOS fdisk utility as you normally would. Because the cylinder size increases to 8 MB under
extended translation, the partition size you choose must be a multiple of 8 MB. If you request a size that is not a multiple of 8 MB, fdisk rounds up to the nearest
whole multiple of 8 MB.
l Silent/Verbose Mode — Displays the host adapter information during system start-up. The default is Verbose.
l Host Adapter BIOS — Enables or disables the host adapter BIOS. The default setting is Enabled.
If you are booting from a SCSI hard-disk drive connected to the host adapter, the BIOS must be enabled. You should disable the host adapter BIOS if the
peripherals on the SCSI bus (for example, CD-ROM drives) are all controlled by device drivers and do not need the BIOS.
l Domain Validation — Instructs the host adapter not to accept a negotiated speed until a validation test is successfully performed. After determining the speed
that a target device is capable of, the host adapter sends a Write Buffer command to the target device. The data transfer occurs at the full speed initially. The
initiator reads and tests the data, and identifies any parity or cyclic redundancy check (CRC) errors. If the test fails, the initiator lowers its speed and repeats the
test. In this manner, a compatible speed will be found and locked in before user data transfers begin. The default is Enabled.
l Support Removable Disks Under BIOS As Fixed Disks — Controls which removable-media drives are supported by the host adapter BIOS. The default
setting is Boot Only. The following choices are available.
l Boot Only — Only the removable-media drive designated as the boot device is treated as a hard-disk drive.
NOTE: For many devices, if Send Start Unit Command is set to Yes, the boot routine time will vary depending on how long it takes each drive to start.
NOTE: The setting for BIOS Multiple LUN Support must be Enabled if a tape autoloader is connected.
NOTICE: Back up your hard-disk drive before you change the translation scheme. All data is erased when you change from one translation scheme to another.
NOTE: Several SCSISelect options are not valid unless the host adapter BIOS is enabled.
NOTICE: If a removable-media SCSI device is controlled by the host adapter BIOS, do not remove the media while the drive is on or you may lose data. If
you want to be able to remove media while the drive is on, install your removable-media device driver and set this option to Disabled.