On Wed, 12 Apr 1995 11:14:43 +0400 Hejji Al-Mazroua 7802 said:
>I'm running ADSM/6000 server and i have defined the device class for device
>tape of 8MM with ESTCAPacity=5G. But when i query volume i found one of the
>volumes exceeded the estimated capacity. for example one of the volume
>shows the estimated capacity=5,953.5 MB, Utilization=93.5
>when i first define the volume the Estimated capacity was 5,120
>any idea......
>Thanks in advance, Hejji

I've seen something similar, but in our case the estimate capacity fell to
4,944.  I don't think it happened all at once, but currently all of our
"filling" tapes show an estimated capacity of 4,944.  If I do a Q DEV, the
est capacity shows 5,120.  We have never been able to fill a volume such
that it has as much as 4,944 MB on it.  I suspect that ADSM has some code
somewhere that re-calculates the estimated capacity based on actual
results.  If it does, I would be interested in hearing more about how this
actually works.  I'd also like to understand why we only get around 4.4GB
per 8mm tape, instead of 5GB, as advertised.  We use both client compression
and tape drive compression (exabyte 8500C drives).

..Paul