不对比不知道啊
vps1
dd if=/dev/zero of=test bs=64k count=4k oflag=dsync
4096+0 records in
4096+0 records out
268435456 bytes (268 MB) copied, 2.03067 s, 132 MB/s
vps2
d if=/dev/zero of=test bs=64k count=4k oflag=dsync
4096+0 records in
4096+0 records out
268435456 bytes (268 MB) copied, 7.65242 seconds, 35.1 MB/s
vps3
dd if=/dev/zero of=test bs=64k count=4k oflag=dsync
4096+0 records in
4096+0 records out
268435456 bytes (268 MB) copied, 18.1121 s, 14.8 MB/s