Subject: Re: Stopping SCSI disks
To: Ken Hornstein <>
From: Anders Dinsen <>
List: tech-kern
Date: 01/25/1999 21:58:55
Ken Hornstein wrote:
> >> There should be enough accounting in the kernel to have NetBSD do it
> >> (which would also work for SCSI drives), but no one has yet written
> >> it.
> >
> >I imagined that a solution would be to extend the sd driver with an
> >ioctl command that tells it to spin the drive down and set a flag that the
> >disk has been stopped. On the next access, the driver would know (from the
> >flag) that a start unit command should be sent first (and the flag should
> >be cleared).
> I'd wonder why you would need the userland daemon at all.  The kernel
> really knows everything you need to know; is there anything to gain
> by putting it in userland?

No. Probably not. It's just my viewpoint: Do as much in userland as

> >quite unstable (!). Anyway, I cannot see why we should suffer from that!
> It should be relatively straightforward; just a Simple Matter of
> Programming :-)

Yes. And defining the interface. Anyway I'll have to get off here. I'd
like this feature, but I'm not the programmer for it. Sorry. Should I
file a pr on this?