Change disk and Iometer not start in console

Hi everyone, im new with io analyzer, I read the manual and follow the instructions to change the disk with 100mb to other with 10 GB but when I run any workload I don´t see that the iometer start on console and only generate 40 iops on the vm in the results page. After I delete and create a new disk is necesary to do something else??

Thanks & Regards!!!