Try with this, though I have not tested this.

RMAN> run {
2> allocate channel incr0dsk type disk;
3> allocate channel incr1dsk type disk;
4> backup
5> incremental level 0
6> tag incr0_bkup
7> format '/u07/tapebackup/tape0/fndry_p/%d_%u',
8> '/u08/tapebackup/tape0/fndry_p/%d_%u'
9> (database include current controlfile);
10> release channel incr0dsk;
11> }


'/u08/tapebackup/tape0/fndry_p/%d_%u' : This is one more file system. Make sure that you have space to backup your data. If you need more space add one more channel and point to additional file location.

regards,

abhijit