Specifying backup keys to fdbbackup

How can I specify the key range of a specific tenant to fdbbackup? I have tried specifying -k ‘\x00\x00\x00\x00\x00\x00\x00\x01’ but to no avail.

What is the correct syntax for specifying key bytes?

This issue was unrelated to they syntax I was using, which is correct, but was due to a missing --blob-credentials specified on a backup_agent which prevented the backup from starting.

I could not actually find in the documentation the need to specify this option in backup_agent also and not only in fdbbackup.

There is also no mention of dynamic reloading of the blob credentials file. Is it performed? Can the file be updated and the updates picked up by backup_agent on the fly or should the processes be restarted for that to happen?