Thanks for the information. I just find it odd that this information is 
reported inaccurately. I would assume that the origin of this info 
comes from "encoded" data (codes) located in the device's (hard drive) 
firmware. I am now curious if the inaccurate information is due to 
inaccurate reporting or interpretation of the data by: the device 
itself; the Mac's Open Firmware; or NetBSD?

Jeff



On Saturday, April 3, 2004, at 02:05 AM, der Mouse wrote:

>
>>> disklabel improperly identifies the drive's rpm at 3600--it's a 7200
>>> rpm drive (Seagate Barracuda ST34371N).  Is this a "bug" in
>>> disklabel?
>> I don't know why this is.  Perhaps someone else can answer your
>> question.
>
> This means essentially nothing.  The RPM value is just another number
> the disklabel stores for anyone that might care to look for it, like
> the geometry figures or the text label string in this respect.
>
> Once upon a time, such values were actually useful, because they meant
> you could predict things like how far the disk would rotate while it
> does a seek between tracks and thus you could figure out how much to
> skew the layout of one track with respect to the previous for optimal
> performance.
>
> Since modern disks are invariable ZBR (which means, probably among
> other things, that the sectors/track value varies with cylinder
> number), any attempt to do anything useful with the RPM value is sunk
> before it starts today.  (Unless, perhaps, you create one partition per
> notch, then use something like a ccd to give each one its own label
> with its own geometry values - and even then, I'm not sure anything
> actually pays any attention to the rpm value today anyway.)