Appendix B: Selecting the Best RAID Level ● 154Comparing RAID LevelsUse this table to select the RAID levels that are most appropriate for the logical drives on your storage space, based on the number ofavailable 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. In general, the moredrives, the better the performance.More information about each RAID level is available beginning on page 155.Understanding Drive SegmentsA drive segment is a disk drive or portion of a disk drive that is used to create a logical drive. A disk drive can include both RAID segments(segments that are part of a logical drive) and available segments. Each segment can be part of only one logical drive at a time. If a diskdrive is not part of any logical drive, the entire disk is an available segment.RAID Level Redundancy Disk Drive UsageReadPerformanceWritePerformanceBuilt-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 Yes 67% – 94% ✱ ✱ ✱ ✱ No 6RAID 6 Yes 50% – 88% ✱ ✱ ✱ No 4RAID 60 Yes 50% – 88% ✱ ✱ ✱ No 8Spanned Volume No 100% ✱ ✱ ✱ ✱ ✱ ✱ No 2RAID Volume No 50% – 100% ✱ ✱ ✱ ✱ ✱ ✱ No 4
