Appendix B: Understanding RAID ● 82Selecting the Best RAID LevelUse this table to select the RAID levels that are most appropriate for the logical drives on your storage space, based onthe number of available disk drives and your requirements for performance and reliability.Disk drive usage, read performance, and write performance depend on the number of drives in the logical drive. Ingeneral, the more drives, the better the performance.RAID Level RedundancyDisk DriveUsageReadPerformanceWritePerformanceBuilt-in HotSpareMinimumDisk DrivesRAID 0 No 100% No 2RAID 1 Yes 50% No 2RAID 1E Yes 50% No 3RAID 10 Yes 50% No 4RAID 5 Yes 67 – 94% No 3RAID 5EE Yes 50 – 88% Yes 4RAID 50** Because they support four disk drives only, the ICP9047MA RAID controller can’t support RAID 50 or RAID 60 arrays.Yes 67 – 94% No 6RAID 6 Yes 50 – 88% No 4RAID 601 Yes 50 – 88% No 8
