单项选择题 Which of the following offers the MOST redundancy for a system but is also very costly?（）

单项选择题 A system administrator needs to maintain 1.2TB of storage for a database server. There are six 250GB drives available in the server for storage space. Which of the following RAID configurations would be the BEST choice given that performance and fault tolerance are important factors?（）

单项选择题 An application server is running slowly. After viewing performance monitoring data it is detected that the disk queue length is high.  Which of the following could BEST resolve the situation？（）