After days of research, I just find out that ZFS is the ONLY solution that meet my requirements.
1. survive from silent data corruption and disk failure.
2. flexible in adding/removal of hard disks.
3. support encryption
It is suprised to me that many solutions seem do not care about silent data corruption (SDC) or bad sector. Full disk encryption with LUKS and LVM is not tolerent to SDC. Hardware RAID is not flexible, since I cannot
add various size of hard drives. Software RAID-1 has detection, but not correction. In theory, RAID-1 with three drives could have correction, but it seems no software implementations support. RAID-6 support both detection and correction, but software controlled RAID-6 has performance concern.