# pagecache:

echo 1 > /proc/sys/vm/drop_caches

# dentries + inodes:

echo 2 > /proc/sys/vm/drop_caches

# pagecache + dentries + inodes:

echo 3 > /proc/sys/vm/drop_caches

# linux

free && sync && echo 3 > /proc/sys/vm/drop_caches && free

# ubuntu

echo 3 | sudo tee /proc/sys/vm/drop_caches

 

Сисадмин