We have a client with "normal" internet upload speed (about 10Mbps), but that's just not fast enough for us to get a full cloud image backup to Amazon.
In our office, we have 1Gbps upload speed, so we've hypothesized that we could do an image backup at the client's office to an external drive, bring it to our office, and upload it to Amazon from here.
Here's the catch/question: Could we then enable a block level image backup from the client's office, and it would "append" to the restore we would've done from our office?
Other suggestions are welcome as to how to get a full, updateable, image backup from our client's office.
Make sure that you're at least on version 6.0 when doing that, and you don't need to perform additional steps from "Modifying Data Structure in the Storage". You just need to synchronize the repository on your original machine after transferring the data manually.
Also, since you're using S3 I suggest to edit the plan after initial local upload and enable synthetic full option, that will speed up the backup process significantly and actually allow you to perform proper full backups which are required for purging the old data.
That step was required for old versions of the software because local and cloud backups used different delimiters( the ":" characters). Now the folder structure is identical in both situations, so you don't need to modify it for the purpose of migration/seeding.