Specifications

140 en | Host-side and Drive-side Parameters SCSI to SATA RAID Subsystem | Administrator’s Manual
F.01U.027.802 | V1 | 2006.11 Bosch Security Systems
8.2.2 Drive I/O Timeout
The “Drive I/O Timeout” is the time interval for the controller to wait 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 Drive I/O Timeout value, the drive will be considered as a failed drive.
When the drive itself detects a media error while reading from the drive platter, it usually
retries the previous reading or re-calibrates the head. When the drive encounters a bad block
on the media, it reassigns the bad block onto a spare block. However, it takes time to perform
the above actions. The time to perform these operations can vary between different brands
and different models.
During channel bus arbitration, a device with higher priority can utilize the bus first. A device
with lower priority will sometimes receive an I/O timeout when devices of higher priority keep
utilizing the bus.
The default setting for “Drive 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 while a drive is still retrying, or while a drive is unable to arbitrate the SCSI bus.
Setting the timeout to a greater value will cause the controller to keep waiting for a drive, and
it may sometimes cause a host timeout.
Fig. 8.13 Selecting Drive I/O Timeout
Choose “Drive I/O Timeout –Default (7 seconds),” then press [ENTER]. A list of selections will
appear. Move the cursor bar to a selection, then press [ENTER]. Choose Yes in the dialog box
that follows to confirm the setting.