Advanced Host Adapter Settings - Dell 4100 User Manual

•
ENABLE DISCONNECTION
called disconnect/reconnect) determines whether the
host adapter allows the SCSI device to disconnect
from the SCSI bus. Enabling disconnection allows
the host adapter to perform other operations on the
SCSI bus while the SCSI device is temporarily dis-
connected. The default setting is
Leave
ENABLE DISCONNECTION
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
better performance.
•
INITIATE WIDE NEGOTIATION
whether the host adapter attempts 16-bit data transfer
instead of 8-bit data transfer. The default setting is
.
YES
NOTE: Some 8-bit SCSI devices may have trouble
handling wide negotiation, which may result in
erratic behavior or a hang condition. For these
devices, set
INITIATE WIDE NEGOTIATION
When this option is set to
attempts 16-bit transfer. When this option is set to
, 8-bit data transfer is used unless the SCSI device
NO
itself requests wide negotiation. The effective trans-
fer rate is doubled when 16-bit data transfer is used
because the data path for wide SCSI is twice the size
of normal 8-bit SCSI.
•
SEND START UNIT COMMAND
mines whether the start unit command is sent to the
SCSI device at boot. The default setting is
Setting this option to
computer's power supply by allowing the host
adapter to start SCSI devices one at a time when you
boot your computer. When this option is set to
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.
NOTE: For many devices, if
is set to , the boot time will vary
MAND YES
depending on how long it takes each drive to start.
3-4 Dell PowerEdge 4100/180 and 4100/200 Systems User's Guide
. This option (sometimes
.
YES
set to if two or
YES
to to achieve slightly
NO
. This option determines
to
NO
, the host adapter
YES
. This option deter-
YES
reduces the load on your
YES
SEND START UNIT COM-

Advanced Host Adapter 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.
•
HOST ADAPTER BIOS
ables the host adapter BIOS. The default setting is
ENABLED
NOTE: Several SCSISelect options are not valid
unless the host adapter BIOS is enabled.
If you are booting from a SCSI hard-disk drive con-
nected 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.
•
SUPPORT REMOVABLE DISKS UNDER BIOS AS FIXED
. This option controls which removable-media
DISKS
drives are supported by the host adapter BIOS. The
.
default setting is
are available.
CAUTION: 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
.
—
BOOT ONLY
designated as the boot device is treated as a
hard-disk drive.
,
NO
—
ALL DISKS
ported by the BIOS are treated as hard-disk
drives.
—
DISABLED
treated as hard-disk drives. In this situation,
software drivers are needed because the drives
are not controlled by the BIOS.
. This option enables or dis-
.
. The following choices
BOOT ONLY
.
. Only the removable-media drive
. All removable-media drives sup-
. No removable-media drives are