Tuning the OS on which is running a database server is important to get good performance for an application. Here are some general guidelines from when tuning your environment.
First, be sure to have a correct RAID strategy for your disks, depending partially on their type and their numbers, taking the following into consideration:
RAID1 is good for redundancy for medium workloads, and can provide good performance for read applications.
RAID0+1 is good for redundancy, better performance than RAID5 but is expensive.
RAID5 should be used for large workloads with more than three disks. It can also be good for parallel load.