ジャーナルを使用してジャーナルの有効期限を強制する方法は？

が利用可能でなければなりません--vacuum-time。以下に示すタスクは、現在アクティブなログファイルをアーカイブに循環し、すべてのログをクリーンアップしてそのログを10日間のみ保持します。

journalctl --rotate --vacuum-time=10days    

マニュアルページから直接：

--vacuum-size=, --vacuum-time= and --vacuum-files= may be combined
       in a single invocation to enforce any combination of a size, a time
       and a number of files limit on the archived journal files.
       Specifying any of these three parameters as zero is equivalent to
       not enforcing the specific limit, and is thus redundant.

       These three switches may also be combined with --rotate into one
       command. If so, all active files are rotated first, and the
       requested vacuuming operation is executed right after. The rotation
       has the effect that all currently active files are archived (and
       potentially new, empty journal files opened as replacement), and
       hence the vacuuming operation has the greatest effect as it can
       take all log data written so far into account.