# 测试写入20Gb文件
sync && time -p bash -c "(dd if=/dev/zero of=test.dd bs=1000K count=20000;sync)"
以下为10.10.14.199的测试数据：
20000+0 records in
20000+0 records out
20480000000 bytes (20 GB) copied, 85.524 s, 239 MB/s
real 87.24
user 0.03
sys 24.67
-- 定州
[root@cloudplatform ~]# sync && time -p bash -c "(dd if=/dev/zero of=test.dd bs=1000K count=20000;sync)"
20000+0 records in
20000+0 records out
20480000000 bytes (20 GB) copied, 75.9612 s, 270 MB/s
real 89.54
user 0.01
sys 16.38
You have new mail in /var/spool/mail/root
=========================================================================
# 测试读取20Gb文件
echo 3 > /proc/sys/vm/drop_caches && time -p dd if=test.dd of=/dev/null bs=1M
以下为10.10.14.199的测试数据：
19531+1 records in
19531+1 records out
20480000000 bytes (20 GB) copied, 59.7922 s, 343 MB/s
real 59.84
user 0.03
sys 18.56
-- 定州
[root@cloudplatform ~]# echo 3 > /proc/sys/vm/drop_caches && time -p dd if=test.dd of=/dev/null bs=1M
19531+1 records in
19531+1 records out
20480000000 bytes (20 GB) copied, 54.1228 s, 378 MB/s
real 54.22
user 0.03
sys 14.28
You have new mail in /var/spool/mail/root
=========================================================================
# 删除临时文件
rm -rf test.dd