Patrick Santucci ([log in to unmask]) wrote:
: Can anyone tell me if the INTER option actually improves throughput on a
: STORE operation? My manager says he read something somewhere at some
: time (nice and specific, huh?) that said it didn't actually make any
: difference.
Using INTER, I have seen a 3-4% faster backup to dds-3 drives using software
compression
for a backup that normally takes 4 to 5 hours.  I think (based on conjecture)
that the gains result when the compression of some files is extremely high
(like unused space in Image datasets).  The manual says the improvement comes
from reducing delays in accessing the data on the discs.  With todays faster
discs, the gains are not too significant.  Once you use MAXTAPEBUF, you've
got most of the performance gains possible.  On our systems, software
compression is faster that DDS-3 hardware compression and uses slightly less
tape (thereby keeping a backup on one tape on at least one of our boxes).

I read somewhere at some time,
that managers don't know how to read and are just
faking it by pretending that they remember stuffi
about which they have no clue!

Maybe I'll get to play with DLT's someday.  But right now, dual DDS-3's do
the job on our biggest system of 36.7G with 60% compression in 4 hours 24
minutes with an average transfer rate of 431 to 483 K/S.
--
 [log in to unmask] HP CSBU R&D  Roseville, CA