Noob question here:
A typical HW RAID 1 is good for dealing with a drive failure, but really lousy for fixing silent data corruption. IE, a controller that performs a consistency check can detect a difference between the two drives, but the controller has no idea which drive has the correct (uncorrupted) data.
With FreeNAS and ZFS, if I'm understanding this correctly, a 2 drive mirror doesn't have this problem because all writes are checksummed. So, if a consistency error is detected, the SW can consult the checksum to figure out which drive has the correct (uncorrupted) data. Is this accurate? Or do I need a 3-way mirror so there are three drives to consult?
A typical HW RAID 1 is good for dealing with a drive failure, but really lousy for fixing silent data corruption. IE, a controller that performs a consistency check can detect a difference between the two drives, but the controller has no idea which drive has the correct (uncorrupted) data.
With FreeNAS and ZFS, if I'm understanding this correctly, a 2 drive mirror doesn't have this problem because all writes are checksummed. So, if a consistency error is detected, the SW can consult the checksum to figure out which drive has the correct (uncorrupted) data. Is this accurate? Or do I need a 3-way mirror so there are three drives to consult?