Check to see if you are using large tape block support (256K data blocks on 
DLT),
also, what format did you specify when you defined the deviceclass (i.e., 
DLT35C,
DRIVE, etc.)

John W. Stephens wrote:

> I am running ADSM version 3.1.0.2 with all version 3 clients. The tape storage
> hardware is DLT7000 drives with the latest STK firmware 7.0. The tape media is
> Fuji DLT_IV cartridges.
>
> I am concerned that I am not getting the compression DLT 7000 media should
> give. I am not running any client compression, hoping to really verify how 
> good
> or bad the hardware will compress. Does anyone have any ideas on how to
> accurately measure this or has anyone experienced this same scene.
>
> Volume Name               Storage      Device      Estimated    Pct   Volume
>                           Pool Name    Class Name   Capacity   Util   Status
>                                                         (MB)
> ------------------------  -----------  ----------  ---------  -----  --------
> DMM558                    NOTES_TAPE   DLT7000      30,180.7   98.4    Full
> DMM567                    NOTES_TAPE   DLT7000      30,391.8  100.0    Full
> DMM574                    NOTES_TAPE   DLT7000      30,485.4  100.0    Full
> DMM576                    NOTES_TAPE   DLT7000      30,189.2  100.0    Full
>
> Thanks,
> John Stephens