root@vtt9:/mnt# dd if=/dev/zero of=./largefile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 0.731311 s, 1.5 GB/s
root@vtt9:/mnt# sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches"
root@vtt9:/mnt# dd if=./largefile of=/dev/null bs=4k
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB) copied, 2.66522 s, 403 MB/s