To add to that, one will very quickly find that RAID5 really isn't a good idea for big drives if one reads around. The reason being that for larger drives, res

To add to that, one will very quickly find that RAID5 really isn't a good idea for big drives if one reads around. The reason being that for larger drives, resilvering can take so long that secondary failures become probable or—in bad cases—even virtually guaranteed (This is the same probably the WD SMR drives had, but it exists even on normal drives if they get big enough). For this reason, for modern large drives, most people recommend at least RAID6 (known as RAID-Z2 on ZFS), which means you have two drives worth of parity as compared to RAID5's single one. Of course, this means that you need at least four drives for it to be worthwhile, and most people realistically end up going for around six disks, otherwise you are spending a lot of your total cost on parity.