NAS Drive Expansion?

[Enquiries]

I have some questions relating to drive expansion on SHR/BTrFS, QTS/Ext4 and QTS-hero/ZFS. On each of these combinations, ...

(1) Can you begin with 1 drive without being locked into JBOD, RAID 0, RAID 1 or RAID 5?
(2) Can you begin with RAID 1, and later, easily change/expand to RAID 5?
(3) Can four drives set up as two RAID 1 pairs be easily expanded to a 4-drive RAID 5?
(4) I know that SHR/BTrFS allows expansion with larger drives without loosing their capacity. Can either of the others do this?
(5) In each of the combinations, if an additional drive is added to a RAID 5, can the data be evenly distributed over the whole RAID? ...easily?

Thank you in advance for the assistance.

[ed]

On all systems, you can start with a single drive, or any number of drives and expand your chosen RAID later.You can start with a RAID1 and migrate to a different RAID later. The only exclusion is RAID0.You can set up two RAID1 pairs, but you can not merge them into a different RAID. You change each of these two RAIDs into something else though.Only SHR allows you to mix drives with different capacities. Other RAID types will see bigger drives as big as the smallest drive in the RAID.If you add another drive to a RAID5 or any other RAID, data will be re-written evenly across all drives. This is how RAID works in order to make redundancy work.I hope this helps.