It is best practice to place members of a group on a multiplexed redo log on different physical disks. For instance, if you have two groups of multiplexed redo log members, make sure to place each member on a different disk. This practice helps avoid contention between LGWR and ARCN. In this case, however, we have two redo log groups with four members each. Instead of having one member on each group disk, it is recommended that we have two members in each group. This will total up to four disks in total
