Re: [patch] My AMD IDE driver, v2.7

Vojtech Pavlik
2002-03-19T09:29:59Z

On Mon, Mar 18, 2002 at 08:20:05PM +0100, Pavel Machek wrote:
> > commands. With the proper sequencing, you can even do power management
> > of the drives in userspace. You don't want to do system suspend/resume
> > that way, but you can certainly have a userspace policy daemon running,
> > that powers-down and powers-up the drives, etc.
>
> See noflushd, Hdparm is able to powersave disks well, already, and it
> was in 2.2.X, too.

Not all of them safely, though. Many a drive will corrupt data if it
receives a command when not spinned up. You need to issue a wake command
first, which hdparm doesn't, it just leaves it to the kernel to issue a
read command or whatever to wake the drive ...

--
Vojtech Pavlik
SuSE Labs