Stateless tape model

Rob Basham/Tucson/IBM robbyb at
Mon Aug 28 07:09:26 PDT 2000

* From the T10 Reflector (t10 at, posted by:
* "Rob Basham/Tucson/IBM" <robbyb at>
These are good comments.  Your second comment really gets to the heart of
the matter and the main question I have been asking myself:
Are we going stateless, or is this just a way to make the state transitions
explicit?  If the answer is truly stateless, a new model is in order.
Otherwise, it seems to me this fits inside the streaming command set.

At this point, I'm open to going either way with this.  My initial leaning
is to not make this truly stateless.  Tape drives are streaming devices.
Particularly when they are writing it is difficult to envision a stateless
model.  On reads a stateless model makes more sense.

Along with introducing the proposal, this is the only issue I want to bring
up at the meeting in September.  Once we decide this question, we can go
off and work on the details.

Rob Basham

(Ralph's comments below)

Comments embedded.

JoeBre at wrote:

> (4 or 6?) byte absolute LBAs should be 8 byte:

8 byte LBAs, absolutely.  If larger CDBs are needed, let's find the
operation codes and do it.

> 3.5 - SPACE(10)...


If the base model for stateless tapes is disks, then the SEEK is the right

> Perhaps we should define a new Device Type identifier for Stateless
Stream Device.

By all means a new Device Type seems in order.



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