Remember, I once built a "scratch NAS"? Well, scratch says it all. At one stage, the data will be destroyed. And this is exactly what I did today (after having stored the data safely in a RAIDZ-1).
Here comes the trick, I reconfigured FreeNAS to a ZFS mirrored array. Now we have same primitive data safety, however, the disk-space is now down to 1.8TB.
The experiment is the following, ZFS is set to compression and deduplication, while the server got 8GB of RAM only.
I wonder if 8GB for 2TB would be enough for home use, or is the rule really is to use 16GB for 1TB.
Will update on the outcome.