Fsync理解
Linux 中直接 I/O 机制的介绍:
https://www.ibm.com/developerworks/cn/linux/l-cn-directio/
文件系统缓存,filesystem cache
https://blog.csdn.net/shb_derek1/article/details/99681871
深入理解Fsync
https://www.cnblogs.com/hustcat/archive/2013/08/26/3283955.html
PostgreSQL why not DirectIO for datafile?
http://digoal.lofter.com/post/6ced3_6d2e8a3
严以律己、宽以待人