Planning: MD3200i Series Storage Array Terms and Concepts 41Each RAID level provides different performance and protection. You mustselect a RAID level based on the type of application, access, fault tolerance,and data you are storing.The storage array supports RAID levels 0, 1, 5, 6, and 10. The maximumnumber of physical disks that can be used in a disk group depends on theRAID level:• 192 for RAID levels 0, 1, and 10• 30 for RAID levels 5 and 6.RAID Level UsageTo ensure best performance, you must select an optimal RAID level when youcreate a system physical disk. The optimal RAID level for your disk arraydepends on:• Number of physical disks in the disk array• Capacity of the physical disks in the disk array• Need for redundant access to the data (fault tolerance)• Disk performance requirementsRAID 0RAID 0 uses disk striping to provide high data throughput, especially for largefiles in an environment that requires no data redundancy. RAID 0 breaks thedata down into segments and writes each segment to a separate physical disk.I/O performance is greatly improved by spreading the I/O load across manyphysical disks. Although it offers the best performance of any RAID level,RAID 0 lacks data redundancy. Select this option only for non-critical data,because failure of one physical disk results in the loss of all data. Examples ofRAID 0 applications include video editing, image editing, prepressapplications, or any application requiring high bandwidth.RAID 1RAID 1 uses disk mirroring so that data written to one physical disk issimultaneously written to another physical disk. This RAID level offers fastperformance, the best data availability, and the highest disk overhead. RAID 1
