time dd if=/dev/zero of=/shopcvs/tmp/test.img bs=1M count=2k conv=fdatasync 2048+0 records in 2048+0 records out 2147483648 bytes (2.1 GB) copied, 2.71921 s, 790 MB/s real 0m2.840s user 0m0.000s sys 0m2.133s
time dd if=/dev/zero of=/shopcvs/tmp/test.img bs=1M count=2k conv=fdatasync 2048+0 records in 2048+0 records out 2147483648 bytes (2.1 GB) copied, 2.71921 s, 790 MB/s real 0m2.840s user 0m0.000s sys 0m2.133s