What is RAID 5?

RAID 5 is a RAID level that uses disk striping with parity, which is spread across all drives in the array, providing a secure data storage solution.

In exchange for only a small amount of storage space, RAID (Redundant Array of Independent Disks) offers one drive of redundancy. Because data and parity are striped across the array, no single disk is a bottleneck. A RAID 5 array requires at least three hard disk drives, although we see arrays with more. RAID 5, like RAID 0, stripes data across all the drives in the array, offering more usable storage than RAID 1. In addition, parity data is striped too, making RAID 5 one of the most secure RAID setups.

RAID 5’s benefits come from its combination of disk striping and parity. Disk striping provides greater speeds, as all the read/write heads are in operation at once. For data redundancy, RAID 5 uses parity over mirroring. Because the parity data is also striped, a RAID 5 system can be rebuilt from any drive in the array.

For all its advantages, there are some drawbacks to RAID 5. As with all RAID storage solutions, RAID 5 isn’t a logical backup; there is no second copy of the data without a backup. Data loss can still occur through human error, malware, or a natural disaster like a fire or a flood. There is also a risk that multiple drives in the array fail simultaneously due to a power surge.