Hi, I hit this a few months ago. It works on us-east-1 because V2 is still enabled on regions created before Jan 30 2014. (I think general rule of thumb is it works in US regions only)
- AWS Signature V4 needed for backup to S3 bucket encrypted with AWS KMS - #13 by SteavedHams (The github link in that post is broken now - see foundationdb/S3BlobStore.actor.cpp at master · apple/foundationdb · GitHub )
- See the second “Note” in Authenticating Requests (AWS Signature Version 4) - Amazon Simple Storage Service
I run FDB in a wrapper service, in non-US deployments I configured it to take the backup locally, then the wrapper service zips the backup files and uploads it to S3.