RAID 1 MIRRORING
This type of RAID array is commonly referred to as a “disk mirroring” solution. RAID 1 will be implemented with at least two disks (and always with an even number of disks).
With RAID 1 the same data is written on all disks. With RAID 1 you constantly have at least two copies (depending on how many disks you have) of all of your data so should something happen to one of your disks, you’ll have a complete and functional drive to work off of, all thanks to the RAID 1 system.
RAID 1 can also provide I/O performance improvement for read operations. Having the data in two copies means being able to read it simultaneously so the read I/O speed can be up to twice as fast.