Which RAID level is best for my application?

Redundant Array of Independent Disks (RAID) describes a storage solution in which part of the storage capacity stores redundant information about user data stored on the remainder of the storage capacity. The redundant information enables regeneration of user data if one of the disk physical disks in the fails.

RAID relies on a series of configurations, called levels, to determine how user data and data are written to and retrieved from the disk physical disks. RAID 1/10, RAID 3, RAID 5, and RAID 6 write redundancy data to the disk physical disk media for fault tolerance. The redundancy data might be a copy of the data (mirrored) or an error-correcting code derived from the data. If a disk physical disk fails, you can use the redundancy data to quickly reconstruct information on a replacement disk physical disk.

RAID Level Performance and Data Protection Summary

RAID Level	Data Protection Available
RAID 5 or RAID 6	RAID 5 or RAID 6 are best for multiuser environments, such as database or file system storage, where typical I/O size is small, and there is a high proportion of read activity. RAID 5 or RAID 6 is the most cost-effective RAID levels that provide redundancy protection. If a single disk physical disk fails in a RAID 5 or RAID 6 disk group, all of the associated become degraded but the redundant information enables the data to be accessed. If two or more disk physical disks fail in a RAID 5 disk group, all of the associated virtual disks fail, and all data will be lost. If three or more disk physical disks fail in a RAID 6 disk group, all of the associated virtual disks fail, and all data will be lost.
RAID 3	RAID 3 is best for large data transfers in applications, such as multimedia or medical imaging, that write and read large sequential chunks of data. This RAID level offers redundancy protection, but any two disk physical disk failures in the same disk group result in data loss. If a single disk physical disk fails in a RAID 3 disk group, all of the associated virtual disks become degraded, but the redundant information enables the data to be accessed. If two or more disk physical disks fail in a RAID 3 disk group, all of the associated virtual disks fail, and all data is lost.
RAID 1/10	RAID 1/10 offers high performance and maintains identical copies of data on disk physical disk pairs, also known as mirrored pairs. Half of the disk physical disks are available for storing user data. Disk physical disk pair failure causes data loss. The strength of this RAID level is high safety and data availability. Loss of a mirrored pair of disk physical disks results in data loss. If a single disk physical disk fails in a RAID 1 disk group, all of the associated virtual disks become degraded, but the mirror disk physical disk allows the data to be accessed. RAID 1/10 can survive multiple disk physical disk failures as long as no more than one failure exists per mirrored pair. If a disk physical disk-pair fails in a RAID 1/10 disk group, then all of the associated virtual disks fail, and all data is lost.
RAID 0	RAID 0 offers high performance, but it does not provide any data redundancy. If a single disk physical disk fails in a RAID 0 disk group, then all of the associated virtual disks fail, and all data is lost.