Hi Maporce!
I don't think you can turn of hardware compression on a 3570 drive. So
hardware compression IS on in your case.
The native capacity of a 3570 cartridge is 5 Gb. (7 Gb. for the new XL
tapes). The 3570 drive offers compression and if you send uncompressed data
to ADSM you are likely to see a 1:3 compression, so the tape can contain up
to 15 Gb. However, you are sending already compressed data to ADSM (you say
you have compression on at the client side). That's why hardware compression
doesn't help you. You can't gain from compressing compressed data.
ADSM reports the amount of (already compressed at the client side) data
written to the tape which will never be much more than the native tape
capacity: 5 Gb.
Kindest regards,
Eric van Loon