在 Ubuntu 上运行更新后，我收到有关我的 ZFS 文件系统的警告。是否有可用于删除旧快照的实用程序或脚本？以下是留言：
ERROR couldn't save system state: Minimum free space to take a snapshot and preserve ZFS performance is 20%.
Free space on pool "rpool" is 10%.
Please remove some states manually to free up space.