清理缓存

1. Clear PageCache only.

sync; echo 1 > /proc/sys/vm/drop_caches

2. Clear dentries and inodes.

sync; echo 2 > /proc/sys/vm/drop_caches

3. Clear pagecache, dentries, and inodes.

sync; echo 3 > /proc/sys/vm/drop_caches

参考资料

https://www.tecmint.com/clear-ram-memory-cache-buffer-and-swap-space-on-linux/