DAT Drive configuration (Urgent)

Dear Friends,

I am having HP9000 E class (E45 ) HP server with HP-UX 10.X. I am having dds model HP35470A (capacity 2/8)which is working fine.

I have removed the dds2 (DAT) Drive Seagate STD 28000N (capacity 4/8)from Sun Ultra Enterprise II and fix it to HP9000 E class machine it has dected the tape drive and given tape device /dev/rmt/3m.

I tried the tar backup with following command :
# tar cvf /dev/rmt/3m .
It is giving me error :- can not write device /dev/rmt/3m .

Kind ly help me st the earlist.

Regards

Dattatray V. Bhagwat