Disconnect, Read write i/o time-out (seconds), Note – LSI SYM22801 User Manual
Page 54: Scan for device at boot time, Scan for scsi logical units (luns), Queue tags, Initial boot, Format device
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Configuring the Host Adapter
Disconnect – SCSI devices have the ability to disconnect from the
initiator during an I/O transfer. This disconnect option frees the SCSI Bus
to allow other I/O processes. This option tells the host adapter whether
or not to allow a device to disconnect. Some devices run faster with
disconnects enabled (mostly newer devices), while some run faster with
disconnects disabled (mostly older devices).
Read Write I/O Time-out (seconds) – This option sets the amount of
time the host adapter waits for a read, write, or seek command to
complete before trying the I/O transfer again. Since this provides a
safeguard allowing the system to recover if an I/O operation fails, it is
recommended that you always set the time-out to a value greater than
zero.
Note:
A zero value allows unlimited time for an operation to
complete and could result in the system being hung-up.
Scan for Device at Boot Time – Set this option to “No” if there is a
device that you do not want to be available to the system. Also, on a bus
with only a few devices attached, you can speed up boot time by
changing this setting to “No” for all unused SCSI IDs.
Scan for SCSI Logical Units (LUNs) – Set this option to “No” if
problems arise with a device that responds to all LUNs whether they are
occupied or not. For example, if a SCSI device with multiple LUNs is
present on your system but you do not want all of those LUNs to be
available to the system, then set this option to “No.” This will limit the
scan to LUN 0 only.
Queue Tags – If the device driver has the capability, this option allows
the user to enable or disable the issuing of queue tags during I/O
requests.
Initial Boot – This option allows any device attached to the first adapter
to become the boot device. It provides the users of non-BBS personal
computers with some of the flexibility of a BBS machine.
Format Device – If enabled, this option allows the user to low-level
format a magnetic disk drive. Low-level formatting will completely and
irreversibly erase all data on the drive. Formatting will default the drive
to a 512-byte sector size even if the drive had previously been formatted
to another sector size.