All our servers are setup using hardware RAID 10 with BBU. RAID 10 (Redundant Array of Independent Drives) is an advanced way of storing data to gain redundancy and performance. It divides and replicates data among multiple disks and requires a minimum of 4 disks to set up.
The high performance of RAID 10, and its ability to perform many simultaneous write options makes it suited to mission-critical database servers. It is the best option for I/O-intensive applications, including email, web servers, databases and operations that require high disk performance and little to no downtime.
One of the biggest advantages of RAID 10 is data safety. RAID 10 provides fault tolerance for at least 1 disk failure, that means, if a disk fails, data can be retrieved from other disks. If you are on a server that stores data on a single disk or on a RAID 0 or RAID 1 (02 disks), your data is lost when a single disk fails.
RAID 10 vs RAID 5 vs RAID 1 vs RAID 0
RAID 10 provides lower I/O latency, superior throughput and data safety to all other RAID levels. It grants 4x read, 2x write speed gain and at least 1 disk failure fault tolerance. RAID 5 or RAID 1 only provides 2x read speed but no write speed gain. RAID 0 provides 2x read and write speed but no fault tolerance, that means data is lost when a single disk fails.
What is hardware RAID 10?
RAID 10 can be set up using hardware or software. However, a software RAID 10 is not as fast and secure as a hardware RAID 10. A hardware RAID 10 is set up using a dedicated hardware called RAID Controller which has additional RAID cache and can also have a BBU to prevent data loss in the event of a power failure.
What is a BBU?
Though RAID 10 prevents data loss in the event of a disk failure, data can still be lost on a RAID 10 configuration. For example, in the event of an unexpected power loss, any data being written on the RAID will be lost. But a BBU (Battery Backup Unit) supplies power to the cache on the RAID controller during an unexpected power loss to maintain cache data that has not been written to disk.