I had an older MacBook M1 configured with two external drives that were successfully backed up using Dropbox Backup. The backups completed and had been working perfectly for several years automatically updating with any new data.
Today I migrated to a new MacBook M4. The same two physical drives are connected, with the same names and the same data, and I am using the same Dropbox account.
However, Dropbox Backup no longer recognises these drives as the drives that were previously backed up. Instead, it appears to be creating entirely new backup identities and wants to upload terabytes of data again over my home internet connection, which will take several days.
I am struggling to understand why Dropbox Backup cannot recognise that these are the same drives containing the same data that already exists in my Dropbox Backup account.
To make matters worse, I was advised by Google Gemini that deleting the old backup entries would not be a problem because Dropbox would be able to identify the existing cloud data and continue from it. That does not appear to be the case.
My main question is…
Is there a supported method to reassociate or relink existing Dropbox Backup data with the same physical external drives after migrating to a new Mac, or is Dropbox Backup designed in such a way that a full multi-terabyte re-upload is required whenever the backup relationship is broken?
If reassociation is possible, please provide the correct procedure. If it is not possible, please explain why Dropbox Backup cannot continue using the backup data that already exists in my account.
At present I can see multiple backup entries being created for the same drives, which suggests Dropbox is treating them as entirely new backup sources rather than continuing the existing backups.
