The write performance using dd and iozone

[cloudtech]

I would wonder if "dd" does a random IO test and "iozone" does a sequential IO test.

There is a significant difference in the performance of the 2 methodologies.

I search this from Google, people says "dd only does sequential I/O". The iozone results are sequential read and write too.

Also, the disk performance test tool in DSS V6 console use "dd" command too. I cannot test this because my volume group was already created.