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3-18
ASUS PCI-DA2200 User’s Manual
IMPORTANT:
If the drives are configured as “Delay Motor Spin-up” or “Motor Spin-up
in Random Sequence,” some of these drives may not be ready yet for the
controller to access when the system powers up. Increase the disk access
delay time so that the controller will wait a longer time for the drive to be
ready.
3.5.2
SCSI Reset at Power Up
By default, when the controller is powered up, it will send a SCSI bus
reset command to the SCSI bus. When disabled, it will not send a
SCSI bus reset command on the next power-up.
When connecting dual host computers to the same SCSI bus, the SCSI
bus reset will interrupt all the read/write requests that are being
performed. This may cause some operating systems or host
computers to act abnormally. Disable the “SCSI Reset at Power-up”
to avoid this situation.
3.5.3
Disk Access Delay Time
Sets the delay time before the controller tries to access the hard drives after
power-on. The default is 15 seconds.
3.5.4
SCSI I/O Timeout
The “SCSI I/O Timeout” is the time interval that the controller waits
for a drive to respond. If the controller attempts to read data from or
write data to a drive, but the drive does not respond within the SCSI
I/O timout value, the drive will be judged to be a failed drive.
When the drive itself detects a media error while reading from the
drive platter, it will retry the previous reading or recalibrate the
head. When the drive has encountered a bad block on the media, it
has to reassign the bad block to another spare block. However, all of
this takes time. The time to perform these operations can vary
between different brands and models of drives.
During SCSI bus arbitration, a device with higher priority can utilize
the bus first. A device with lower priority will sometimes get a SCSI
I/O timeout when higher priority devices keep utilizing the bus.
The default setting for “SCSI I/O Timeout” is 7 seconds. It is highly
recommended not to change this setting. Setting the timeout to a
lower value will cause the controller to judge a drive as failed a drive