Software RAID
Software RAID is when the interaction of multiple drives is organized completely by software. RAID stands for redundant array of inexpensive disks.
ZFS
Originally developed by Microsystems for its enterprise-level SANs, later purchased by Oracle, which made it available open-source. Now, it is imported to many Linux distributions.
ZFS performs well, but it costs some RAM to run it. ZFS requires 1Gb of RAM for 1Tb of storage.