Subject: Re: disks write-back cache
To: NetBSD Kernel Technical Discussion List <>
From: Manuel Bouyer <>
List: tech-kern
Date: 04/29/2003 00:21:32
On Mon, Apr 28, 2003 at 06:14:20PM -0400, Greg A. Woods wrote:
> Well, the AWRE and ARRE mode-page bits are indeed the SCSI-specific way
> of saying "automatic sector reallocation on error" (for write and read,
> respectively).  However if other types of storage interfaces have
> similar features then the concept isn't really SCSI-specific.

ha, OK. Well, this could probably go in dkctl then, provided it's just
binary (enable/disable).
For IDE this isn't settable, I don't know for other types of disks
Do we have anything else than the ATA and SCSI command sets for modern
disks ?

> Is there any way to control the bad-sector reallocation ability of
> IDE/ATA drives that do this, or is it always done?

As far as I know there's no control on this, it's always on for writes
and always off for read.

Manuel Bouyer <>
     NetBSD: 24 ans d'experience feront toujours la difference