Recommended drive configuration and upgrade path for new diskless PR4100

Do you have any recommendations for the initial drive configuration for a diskless PR4100?
I’d like to start with minimal expense and about 4TB of usable space, then add storage as needed.

I was originally going to fill 2 bays with 24TB drives and leave 2 bays empty
then as i need more storage, add another 4TB (3
4TB total) drive and then another 4TB (4*4 total) drive in the future.

BUT if i understand correctly, this would require wiping everything when I switch from raid 1 (2 drives) to raid 5 or 10 (4 drives)

What is the best way to start with minimal expense but allow easy future upgrades?

While you would need to wipe the data to switch RAID types, you should have a backup of the data already (if you don’t I Highly recommend making one) on a different drive so it should be a simple process of connecting the backup drive and copying the data back to the My Cloud overnight.

You can configure 24TB (2 drives) as RAID 1. Then in the future when you add 1 more drive 34TB. You can migrate your RAID 1 to RAID 5 without loosing data. The process might take sometime to completed. As the same if you want to add the 4th drive and then migrate to RAID 10. Device will not wipe your data if you do the RAID migrate option.

Thank you for your responses.
I purchased 2*4TB drives with the plan to eventually upgrade to 16TB.

The customer support rep suggested that I would use the “add storage” option for the 3rd and 4th drive but that the drives would remain in Raid1 format.

Good to know that there is also a Migrate option which will let me migrate to raid 5 or 10 without requiring the removal and replacement of all the files.