Compaq Infortrend manual Disk Access Delay Time, Scsi I/O Timeout

Power off all hard drives and controller, and power them on again. Hard drives will not spin-up all at once. The controller will spin-up the hard drives one at a time at the interval of four seconds.

Disk Access Delay Time

Sets the delay time before the controller tries to access the hard drives after power-on. Default is 15 seconds.

Choose “Disk Access Delay Time,” then press [ENTER]. A list of selections displays. Move cursor bar to a selection, then press [ENTER]. Choose Yes in the dialog box that follows to confirm the setting.

SCSI I/O Timeout

The “SCSI 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 SCSI 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 models of drives.

During SCSI bus arbitration, a device with higher priority can utilize the bus first. A device with lower priority will sometimes receive a SCSI I/O timeout when devices of higher priority 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 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

Advanced Configurations 9-20