Drive constantly grinding ...

[Gary E. Bickford]

At 1:46 PM -0600 11/15/98, Justin T. Gibbs wrote:
>What you are hearing is likely what Seagate calls 'dithering'.
>When the drive is otherwise idle, the head is moved to new locations
>periodically so that it doesn't pass over the same piece of media
>for extended periods of time.  The Seagate representative told us
>(Pluto) that this was done to ensure that if a plater contained an
>imperfection that caused the head to 'brush' the platter occassionally
>(not a head crash) the head would not wear out the platter.  For
>real time applications (Pluto offers real time video editor/server
>products) where you want the head to stay where you put it, this
>is somewhat annoying.  Pluto's work around is to send a Test Unit
>Ready command to the drive every 500ms or so which restarts the
>'diterhing timer' and prevents the extra seeks.

Cheetahs have a number of different usage profiles that you can set, ie for
general systems use, video streaming, etc.  I wonder if just setting the
profile to the video streaming mode would fix that.  I've never done it,
just read about it.
Gary E. Bickford, garyb at slb.com
Sr. Systems Administrator, Connect Schlumberger http://www.connect.slb.com

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