Which command conducts a non-cached read test to evaluate storage performance?

The command that conducts a non-cached read test to evaluate storage performance is ioping. This utility is specifically designed to measure the performance of the input/output operations on a storage device, providing real-time feedback on the latency of these I/O operations.

When you use ioping, it sends requests to the specified block device or file and reports the time taken for these requests. This allows you to see how quickly the system can read data directly from the storage without relying on cached data, which gives a more accurate representation of raw storage performance. This is particularly useful when assessing the efficiency of different storage devices or configurations in an environment where real-time performance is paramount.

Using ioping for this purpose is advantageous because it operates at a low level and can reveal insights into the behavior of the underlying hardware, something that more general tools do not always provide. Other options may focus on different aspects of storage testing but do not directly utilize the reading mechanics that bypass cache effects as effectively as ioping does.