One of my client is using DDS3 DAT drive (24 GB in compression mode) The
compression type they are using is, Hardware [If available, otherwise software]
But DAT comes out after coping of 17,832,39.. byte of data and their total
size of data is 18 ~ 19 GB. I had tried all the compression type even only
hardware, but it doesn't work. When the Dat capacity is if 24 GB compression
then why it comes out after 17 GB when taking the backup of 19 GB data.

The specification of Data DAT drive is as follows,
Make : Seagate
Model No. : STD224000N
FRU P/N : 74102101
Model : STD124000N
12/24 GB DDS3 Internal Tape Drive.

If any body has the solution please rely me back.