Linux 我想删除ram缓存，但在ubuntu 18.04.3 Lts 64位上出现权限被拒绝错误

只有

sync

以sudo权限运行，而不是

echo

。你可以这样做：

waseem@waseem-HP-Laptop-14q-cs0xxx:~$ free -h
              total        used        free      shared  buff/cache   available
Mem:           3.7G        1.8G        609M        478M        1.3G        1.2G
Swap:          975M        280M        695M
waseem@waseem-HP-Laptop-14q-cs0xxx:~$ sudo sync; echo 1 > /proc/sys/vm/drop_caches
bash: /proc/sys/vm/drop_caches: Permission denied
waseem@waseem-HP-Laptop-14q-cs0xxx:~$ 

sudo sync; echo 1 | sudo tee /proc/sys/vm/drop_caches >/dev/null