I've had a very similar experience. I migrated to a new Mac using Migration Assistant and Arq no longer sees my long backup history, and is trying to back up everything anew. I was never given the option to "adopt" the old backup set, and Arq and Glacier both see that there are several hundred GB in the vault, but apparently all of that is orphan data that I'll be paying for forever (I guess I could manually delete the vault).
Support was not very helpful in my case either. On the plus side, Arq 4 recommends deleting and recreating your Glacier-backed backup sets anyway...
Did it see your backup folder configuration? If not then you'd have to browse under "Other Backup Sets", select your old computer's backup set and click the "Adopt" button.
If you did see the folders configured, then you've already "adopted" (Migration Assistant copied Arq's config file). In that case it shouldn't have re-uploaded.
OK, it's apparently adopted then. But it shows no backup history and is trying to re-upload everything. My support case is #2152 if you want to look it up.
Hi. Were you able to solve this issue? I am in the same exact situation.
Also, where can you look up support cases for Arq? The website shows no support forum at all...
Thanks
Support was not very helpful in my case either. On the plus side, Arq 4 recommends deleting and recreating your Glacier-backed backup sets anyway...