borg importer
a borg -> borg importer could be used to change stuff that can only be given at repository creation time (borg1: borg init, borg2: borg rcreate), e.g. --encryption mode.
to access the data contained in the existing borg archives, there are 2 options:
- borg extract (might need a lot of space, but should support all metadata on a suitable fs)
- borg mount (does not support all metadata, requires FUSE support)
Would borg export-tar | borg2 import-tar method work for this?
As also presented here https://borgbackup.readthedocs.io/en/master/usage/tar.html#archives-transfer-script
Should take less space than borg extract (?) and provide more metadata than borg-mount.
Time required may be high. But for one time transfer, could be considered okay.
export/import-tar does not support all metadata.