Use RAID 10 on PR4100 with only 2 drives or RAID 1 to RAID 10 without wipe

Hey Guys,

I have just purchased a PR4100 and was wondering if anyone knows whether it is possible to set up in RAID 10 with only 2 drives. My plan is to expand from 2 x 4TB drives to 4 x 4TB drives in the future and expanding from 4TB useable space to 8TB (hope that makes sense due to redundancy) and so was wondering whether RAID 10 can be set up ready for those additional drives later.

Otherwise, if RAID 1 is used, is a wipe required to add 2 new drives and change from RAID 1 to 10.

Hope it is clear what i am trying to achieve.



For RAID 10 you need at least 4 drives. It is not possible to create RAID 10 with only 2 drives.

Hi Hamlet,

I am aware that usually 4 drives are needed for RAID 10 but know that some linux systems allow drives to be set up in RAID 10 with less than 4 drives so that extra drives can added at a later date (effectively acting as RAID 1 until that time). I was wondering if this NAS had the same capabilities?

Link here: Link

If not, I was wondering if anyone knew whether a wipe was needed to go from RAID 1 to 10?


Unfortunately, according to the PR manual (page 54), changing RAID will cause a loss of all data:

WARNING! Changes made to your RAID mode will delete all of your data and your user settings. See “Saving a Configuration File” on page 87 for information on saving your user settings.