Data Guard in R8

Dear all,

Could u tell me related with Data Guard?
- When we use data guard and its size increase, i want to clear its size. How should i do?
- In root after I type command jlogstatus, it shows size(%)
# jlogstatus
.......
.......
/jBase/j5019/logset3/set3_file1: 92.28% capacity
/jBase/j5019/logset3/set3_file2: 92.28% capacity
....... Could u tell me, what is 92.28% capacity? size for store data guard or other? Thanks