online backup

Dear all

I am taking a on;ine backup my datasize 1 TB, my tape drive size is 400 Gb only , I am schdule a online backup through brtools approximately second tape insert after 3 hours when first tape finish .becase we are not avilable in the night , our aim is , when restorh this data , any poblem in database restroration .

thanks

with reagrds

venkat