STORAGE DEVICE INCLUDING NONVOLATILE MEMORY AND MEMORY CONTROLLER AND OPERATING METHOD OF STORAGE DEVICE

An operating method of a storage device includes reading data from a nonvolatile memory using first read parameters and second read parameters and collecting read histories associated with a plurality of read operations. First histories and second histories are determined from the collected read histories. The second read parameters are adjusted according to the first histories, and the first read parameters are adjusted according to the second histories. The read histories include information on read voltages used to perform the read operations, and the first histories and the second histories are determined from the collected read histories according to the number of read voltages having the same level.