Raid Recovery Tips

The most common reason for drives being marked offline is cabling/termination issues. Make sure the cabling is of the highest quality (twisted pair or Teflon ribbon) that’s within SCSI specifications as to maximum bus length, impedance matching, and maximum allowed devices.
For best results, use a system level SCSI terminator (LVD/SE) on the end of the cable, instead of using the last drive for termination. Make sure the hard drives are set to provide SCSI Termination Power, if supported. Rarely is drive firmware an issue more often a SCSI controller BIOS or ASPI driver update.

Try the following troubleshooting steps:

1. Check all…

I have a SCSI RAID controller and the drives keep coming up marked dead/off-line. I can return the drives on-line again, but why is this happening and what can I do to fix it?

Drive randomly marked dead (off line) by SCSI controller.

There are many reasons why a SCSI controller or operating system marks one or more drives off line. Here is a list of common issues, likely to cause a drive to be remarked off line–dead.

It’s important to make sure the cabling, termination, and drive enclosure hardware is suitable based on SCSI specification–or as required by your configuration. Use…