1.) Tune Oracle - tuning SQL statements to reduce unnecessary I/O request is the only guaranteed way to reduce "db file sequential read" wait time.
2.) Tune Physical Devices - Distribute(stripe) the data on diferent disk to reduce the i/o . Logical distribution is useless. "Physical" I/O performance is only governed by "independency of devices".
3.) Faster Disk - Buy the faster disk to reduce the unnecessary I/O request .
4.) Increase db_block_buffers - A larger buffer cache can (not will, "might") help .
Reference :: From Asktom site