Selecting a RAID type for your Server

Knowing which RAID to select for your server can be tricky, so we have provided some details on each RAID type that might help you determine which is best for your business needs.

We offer three types of RAID cards in our HPE Servers. If you require RAID 10,50, or 60, the P840 Controller card is the one you will require. More basic needs for RAID 0,1,5 or 6 can be covered by using the HPE P440 controller card.

RAID 0 combines two or more drives to increase performance and capacity but provides no fault tolerance. A single

drive failure will result in losing all data on the array. RAID 0 is useful for non-critical systems where a high

price/performance balance is required

RAID 1 Minimum of 2 drives for RAID 1 capacity.

RAID 1 is most often implemented with two drives. Data on the drives are mirrored, providing fault tolerance in case

of drive failure. Read performance increases while write performance will be similar to a single drive. A single drive

failure can be sustained without data loss. RAID 1 is often used when fault tolerance is key, while space and

performance are not critical requirements.

RAID 5 Minimum of 3 drives for RAID 5 capacity

RAID 5 provides fault tolerance and increased read performance. RAID 5 can sustain the loss of a single drive. In the

event of a drive failure, data from the failed drive is reconstructed from parity striped across the remaining drives. As

a result, both read and write performance are severely affected while a RAID 5 array is in a degraded state. RAID 5 is

ideal when space and cost are more important than performance.

RAID 6 Minimum of 4 drives for RAID 6 capacity

RAID 6 is similar to RAID 5, except it provides another layer of striping and can sustain two-drive failures. The

performance of RAID 6 is lower than that of RAID 5 due to this additional fault tolerance. RAID 6 becomes attractive

when space and cost are important and sustaining multiple drive failures is required.

RAID 10 Minimum of 4 or 5 drives for RAID 10 capacity

RAID 10 combines the benefits of RAID 1 and RAID 0. Read and write performance is increased, but only half of the

total space is available for data storage. Four or more drives are required making the cost relatively high, but the

performance is great while providing fault tolerance at the same time. In fact, a RAID 10 can sustain multiple drive

failures — provided the failures are not within the same subgroup. RAID 10 is ideal for applications with a high

input/output demand, such as database servers.

RAID 50 Minimum of 6 drives for RAID 50 capacity

RAID 50, also known as RAID 5+0, merges distributed parity (RAID 5) with striping (RAID 0). The benefits of this RAID

level are better write performance, better data protection, and faster rebuilds than RAID 5. Performance does not

degrade as much as in a RAID 5 array because a single failure only affects one array. Up to four drive failures can be

overcome if each failed drive occurs in a different RAID 5 array.

RAID 60 Minimum of 8 drives for RAID 60 capacity

RAID 60 (or RAID 6+0) is a hybrid that offers the distributed double parity of RAID 6 with the straight block-level

striping of RAID 0. As a RAID 0 array striped across RAID 6 elements, RAID 60 (6+0) is a multilevel disk set composed of

RAID 6 sets aggregated at a higher level into a RAID 0 array. A RAID set offers redundancy and can withstand the loss

of up to two disks in each parity set. RAID 60 arrays are more reliable than RAID 50 arrays thanks to the extra parity

disk in RAID 60. But when more than two disks in a single parity set are lost, the RAID 0 set breaks, and data recovery

is needed.