RAID 1 PCI controllers

RAID 1

— mirrored disk array: written data is copied to each individual disk. In other words, each individual drive in such an array is an exact copy of another drive. This provides the highest degree of fault tolerance: the information remains available in full volume as long as at least one disk is working in the array. At the same time, the read speed is quite acceptable, and when using query parallelization, it is even higher than when using a single drive. The main disadvantage of RAID 1 is very high redundancy: the working capacity of the array is equal to the capacity of only one disk.