看下 iostat 的帮助，你就知道哪个指标对 nvme 来说没有啥意义的
%util
Percentage of elapsed time during which I/O requests were issued to the device (bandwidth utilization for the device). Device saturation occurs when this value is close to 100% for devices serving requests serially. But for
devices serving requests in parallel, such as RAID arrays and modern SSDs, this number does not reflect their performance limits.