Subject: SCSI reassign ioctl.
To: None <current-users@NetBSD.ORG>
From: Brian Buhrow <>
List: current-users
Date: 05/09/1995 16:15:02
	Hello listers.  I have some questions about the ability of the NetBSD
scsi subsystem to perform the reassignment of bad blocks.

1.  My understanding is that the scsi system can operate in two modes.  A.
Automatic correction mode, and B.  Manual correction mode.  In A, the scsi
disk automatically moves bad sectors to good portions of the disk as the
errors are discovered.  In the second mode, scsi operations on a bad block
will continue to try and use the bad block until the scsi system is
explicitly told not to, either by locking the sector out, or by remapping
it to a new portion of the physical disk.  In which mode does the netbsd
scsi subsystem operate?

2.  Even if the netbsd scsi system operates in the automatic mode, is it
possible to explicitly give scsi commands to remap sectors of hard disks
through an ioctl interface?

3.  Even if it is possible, is the ability to reassign bad blocks an
extension to the scsi spec which only some controllers are capable of

	If I sound confused with these questions, I am.  What I'm interested in
knowing is if a repair program can be written under NetBSD which will deal
with scsi disks.  What hooks are already in place to get the proper
commands to the scsi devices themselves?

Any help on this matter would be greatly appreciated.