This topic has no direct answer, I just emailed WD support to see if they can “confirm” my question. I currently have a trusted 2TB MyBook Live (single Drive) Upgraded a few years ago for redundancy with the MyCloud Mirror 4TB model, In RAID for 2TB. With my ever expanding Music and Video library, phones and tablets auto backing up to the NAS, i want to double my capacity.
Can I remove 1 of my 2TB WD Red drives, replace it with a 4TB to rebuild the 2TB data on the new 4TB drive? When finished i should be able to swap the last 2TB drive out for a new 4TB to finish the rebuild process. Thematically this is what should happen and not have any issues with data loss.
I understand if i remove 1 of the 2TB drives, i still have all of my data since this is a mirrored copy of the first drive.
Has anyone done the upgrade WITH data and had no data loss/corruption?
I may just backup my NAS to a 4Tb external in an ISO and try the upgrade/rebuild and post a video on Youtube…to confirm or deny.
The 4TB unit may be treated as a 2TB unit in order to provide volume parity. This means the volume will remain 2TB after the second disk is replaced because of the size of the original, repaired volume.
Question is…to expand my NAS…Can I rebuild a 2TB onto a 4TB on Drive 1. When drive 1 is completed the rebuild, Can i replace Drive 2 with a new 4TB to rebuild that portion of the NAS. When completed, I should have all data on 4TB vs 2TB.
You will have to create a new RAID volume. The size of the original volume will be treated as the de-facto base volume.
Having to rebuild the volume using a new 4TB unit while the original volume was 2TB means the 4TB unit will become a 2TB unit, and inserting another 4TB unit (2 physical 4TB untis) will still result in a 2TB volume because that’s the size of the original volume in question. It will not expand and accommodate the remaining space.
Not sure this is a result of the new firmware, and it is counter-intuitive, but it was easy to replace the 2TB drives in My Cloud Mirror (gen 1) 4TB to upgrade to 6TB total. Caveat: I was using the default 2TB total RAID 1 mirrored capacity. Login to the unit as admin, click into “Storage” then “Change RAID Mode” then “RAID 1” and check the box “Expand Capacity” and the “Next” button will activate, so click through. The firmware will step you through replacing drive 1 then drive 2. It takes many hours between steps (full disk copy for RAID 1 mirror), but it worked flawlessly. I upgraded to a couple of 3TB drives (they were cheap…).
The process as you describe it seems logical. Do you know which firmware version your device has been on? I am trying the same thing, but my unit does not offer the “expand capacity” option.
