RAID 10 (RAID 1+0) This level is also known as mirroring with striping. RAID 10 uses a striped array of
disks that are then mirrored to another identical set of striped disks. For example, a striped array can be created by using five disks. The striped array of disks is then mirrored using another set of five striped disks. RAID 10 provides the performance benefits of disk striping with the disk redundancy of mirroring. RAID 10 provides the highest read-and-write performance of any one of the other RAID levels, but at the expense of using twice as many disks.
RAID 50 (RAID 5+0) This is a nested RAID level combining the block-level stripping of RAID 0 with the
parity of RAID 5. It can be thought of as a RAID 0 array consisting of multiple RAID 5 arrays. This level improves upon the write performance of RAID 5 and provides better fault tolerance than a single RAID level. The specific configuration and number of disks will determine the actual availability and performance characteristic of this RAID level. This RAID type is becoming a common feature on even low-end storage devices.
Other RAID levels may offer additional fault tolerance or performance enhancements. These levels generally are proprietary systems. For more information about these types of RAID systems, contact your storage hardware vendor.
RAID 1 is recommended for the system volume in all host server architecture patterns.
RAID 1 or RAID 10 is recommended for the data volumes in the Single Host Server architecture pattern.
RAID 5 and 50 are generally not recommended for virtualization environments due to their inherent write performance penalties.
Storage Controller Architecture The storage controller is either a server add-in card, such as a SCSI or SAS
controller, or a component of a mid- to high-end storage array. The storage controller provides the interface between the disk drives and the server or storage area network. The design factors that impact storage controller performance include the interface or HBA type, the amount of cache, and the number of independent channels.
Disk Controller or HBA Interface The disk controller interface determines the types of drives that can be utilized as
well as the speed and latency of the storage I/O. The table below summarizes the