dd命令测试硬盘IO

1.用Linux自带的命令dd测试硬盘IO，如下
------------------------------------
写：

[root@server102 ~]# time dd if=/dev/zero bs= count= of=/tmp/1Gb.file
+ records in
+ records out
 bytes (1.0 GB) copied, 2.28729 s,  MB/s

real    0m2.375s
user    0m0.079s
sys    0m2.028s

读：

[root@server102 ~]# time dd if=/tmp/1Gb.file bs=64k |dd of=/dev/null
+ records in
+ records out
 bytes (1.0 GB) copied, 1.27014 s,  MB/s
+ records in
+ records out
 bytes (1.0 GB) copied, 1.27062 s,  MB/s

real    0m1.272s
user    0m0.163s
sys    0m1.763s

2.第二种方法

[root@dbserver01 email_info]# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:    MB in  2.00 seconds = 7935.60 MB/sec
 Timing buffered disk reads:  MB in  3.01 seconds = 483.98 MB/sec