Subject: Re: powerhooks and SCSI disks
To: Michael Lorenz <firstname.lastname@example.org>
From: Jason Thorpe <email@example.com>
Date: 12/16/2005 09:05:53
On Dec 16, 2005, at 7:44 AM, Michael Lorenz wrote:
> I'm currently looking for ways to improve power management on
> SPARCbooks, mainly adding things like some sort of standby mode,
> off unused peripherals and so on. We can for instance turn off
> power for
> the internl SCSI disk ( in case a drive wouldn't honour a motor stop
> command ) So, I have a few questions:
What drive would not honor a STOP command? Seems broken... anyway...
> - are there any objections against adding a power hook to sd so it
> flush the drive's cache before we're going to remove power?
This seems like a fine thing to do.
> - is there anything to do after turning the drive back on to resume
I can't think of anything special.
One thing you might want to make sure of is that our SCSI I/O path
can handle the case where a command fails BECAUSE the drive is not
spinning, and can recover by issuing a START command to the drive.