On Wed, 7 Sep 1994 18:37:41 EDT Deba Patnaik said:
>We are using 3490E drives with extended cartridges. ADSM/VM server level is at
>level 0.8. I have defined the mode to be 3490C and Estimated Capacity 800MB
>was about 1400MB to 1600MB. After upgrading to 0.8 level, the server started
>complaining about the media length - and I talked to level 2 and we figured
>may be we better set the LENGTH to ANY.
>Now I notice that the volume occupancy  stays around 800MB. My question is
>should I increase the estimated capacity - since I know from previous volume
>that the extended cartridges can hold around 1600MB ?

Well, I'm at 0.5 and have always seen about 800MB for my 3490E w/extended
cartridges.  I've got them defined as format 3490C and a length of ECCST.
I've always assumed the reason I never saw more data placed on the
cartridges was that all the data here undergoes software compression
on the client side before hitting the hardware compression on the 3490E.
Normally software compression is less efficent for space than hardware
compression and attempting to compress compressed data doesn't get you
much more.

I've never had ADSM running without client compression so I can't say if
that may be your problem, perhaps you've changed to requiring software
compression or maybe your clients were changed on you?  Maybe worth a look
into.

If not, I'd be really interested in how you got 1400MB, I'd love to
increase my storage capacity in the robotic unit by 75+%.  I don't think
changing the estimated capacity would help you though, I have the
capacity set at 775M for the 3490E carts I have and the server has no
problem writing as high as 828M on them.  The server will mount catridges
that have already exceeded their estimated capacity.

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Keith A. Crabb         Keith AT UH DOT EDU
Keith A. Crabb         Keith AT UH DOT EDU
University of Houston  Operating Systems Specialist +1-713-743-1530