How to keep CDR copy after sftp push-receiver activated?

Hello,

I want to keep copy of CDRs after ftp push receiver is sending it to external server. I though account-config options "cdr-output-redundancy = standby-push" does exactly what I want. As Accounting Guide says:

Set this parameter to standby-push to enable the function and enable local storage and implement push capabilities on an HA deployment's standby to protect against CDR data loss.

But it does not keep local copy on standby node. There is no CDR stored in standby node at all. With option "cdr-output-redundancy = enabled" there was at least tmp* file synchronized to standby node, but with "standby-push" there is nothing synced to standby node.