Hi,
This doesn't sound like an I/O Analyzer issue. I/O Analyzer simply invokes Iometer and generates IOs to the target block device. Since VSAN is still in beta, I'd suspect this is more of a VSAN specific issue. Please check vsanDatastore capacity and make sure no more or larger objects are created as desired.
Please bear with us that due to limited resource, we provide supports only for functional issues of I/O Analyzer. If you're still having the disk full error, please contact your local VMware support.
Thanks,
Chien-Chia