ubuntu server 扩容

问题重现：

panic: MISCONF Redis is configured to save RDB snapshots, but it is currently not able to persist on disk. Commands that may modify the data set are disabled, because this instance is configured to report errors during writes if RDB snapshotting fails (stop-writes-on-bgsave-error option). Please check the Redis logs for details about the RDB error.

查看redis日志，显示：

Write error saving DB on disk: No space left on device

问题解决：（未测，系同事处理的）