Which RAID Array is Better to Use for 4 Drives

You have 4 drives - what to do now?

Okay, you have four disks, but what do you do next? Which RAID is Best for You?

This article will walk you through the nuances of common four-drive arrays and guide you to the best option to make your choice easier.

RAID 1 consists of at least two drives, so four drives are acceptable. The data distribution mechanism here is mirroring. This type of array has excellent performance, where the write and read speed is high. However, you can only use 50 percent of independent disks for data storage. If free space plays a big role for you, then this option is not for you.

RAID 10 is two or more RAID 1 array of the same size. In this case, the storage engine combines mirroring with striping. The result is the perfect combination of excellent data protection and high performance. It should be noted that the most optimal RAID with four drives is RAID 10. The disk segment size is the size of the smallest disk in the array. And if, for example, an array with two 250 GB drives and two 400 GB drives can create two mirrored 250 GB disk segments, which adds up to 500 GB for the array. It should be noted that the most optimal RAID is RAID 10.

RAID 5 consists of a minimum of three drives and uses both striping data and parity data. Parity data are responsible for protecting data while striping data are responsible for improving performance. The redundancy in this array is used to recreate data in the event of a disk failure. And the parity data are evenly distributed across the stored data drives.

RAID 50 consists of at least six drives, so the price range for this array is impressive. This array is configured as two or more RAID 5 arrays. It distributes the stored data and parity data across all drives in both RAID 5 arrays. RAID 50 also offers high performance, fault tolerance, and high data transfer rates.

Here also, the disk segment size is the size of the smallest disk in the array. Thus, if there are three 250 GB hard drives and three 400 GB hard drives, then they contain two identical RAID 5 arrays with 500 GB of stored data and 250 GB of parity data. Thus, a RAID 50 can contain 1000 GB of stored data and 500 GB of parity data.

RAID 6 (minimum of 4 disks) is similar to RAID 5, but RAID 6 arrays include two independent parity datasets instead of one that is striped separately across all disks in the array. RAID 6 can withstand the failure of two drives at once, and this property makes the array as resilient as possible. But this cannot but affect performance, as double counting requires additional resources.