An arithmetic operation unit receives a request to update a first data group during restoration using first history information and generates second history information indicating a history of updates. The arithmetic operation unit predicts a time taken until completion of restoration using the second history information on the basis of an amount of the second history information. The arithmetic operation unit compares the predicted time with a threshold and limits at least part of updates of the first data group during the restoration using the second history information on the basis of the comparison result.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A non-transitory computer-readable storage medium storing therein an update control program that causes a computer to perform a process, the computer being in a system which includes a first storage device and a second storage device, the process comprising: receiving a request to update a first data group stored in the first storage device during restoration of a second data group stored in the second storage device using first history information indicating a history of updates of the first data group; generating second history information indicating a history of updates based on the received request; predicting a time taken until completion of restoration using the second history information based on an amount of the second history information; and limiting, based on the predicted time, at least part of updates of the first data group during the restoration using the second history information. 2. The computer-readable storage medium according to claim 1, wherein the limiting includes comparing the predicted time with a threshold and selecting software for which the update is limited from a plurality of software making requests to update the first data group based on the predicted time when the predicted time is longer than the threshold. 3. The computer-readable storage medium according to claim 2, wherein the selecting includes selecting software for which the update is limited for each classification in order from the lowest priority so that a probability that the first data group is not updated for an elapsed time equal to or longer than the predicted time is equal to or higher than a predetermined probability by referring to information indicating priorities in accordance with the classifications to which the plurality of software belong, respectively. 4. The computer-readable storage medium according to claim 3, wherein the selecting includes accepting a user's input specifying a time that is spent on restoration of the second data group using a plurality of pieces of history information and calculating the predetermined probability based on the specified time. 5. The computer-readable storage medium according to claim 3, wherein the process further includes, before the selecting, measuring the number of access requests to the first data group received according to the elapsed time and the number of update requests of the access requests for each of the classifications and calculating, based on the measurement result, a probability that the first data group is not updated with respect to the elapsed time for a plurality of selection patterns when selecting a classification for which the update is limited in order from the lowest priority, and wherein the selecting includes specifying, from among the plurality of selection patterns, a selection pattern with which a probability that the first data group is not updated with respect to the elapsed time equal to or longer than the predicted time is equal to or higher than the predetermined probability. 6. An information processing system including a first storage device and a second storage device, the information processing system comprising: an information processing apparatus configured to: receive a request to update a first data group stored in the first storage device during restoration of a second data group stored in the second storage device using first history information indicating a history of updates of the first data group; generate second history information indicating a history of updates based on the received request; predict a time taken until completion of restoration using the second history information based on an amount of the second history information; and limit, based on the predicted time, at least part of updates of the first data group during the restoration using the second history information. 7. A data update control method of a system which includes a first storage device, a second storage device, and an information processing apparatus, the method comprising: receiving, by a processor of the information processing apparatus, a request to update a first data group stored in the first storage device during restoration of a second data group stored in the second storage device using first history information indicating a history of updates of the first data group; generating, by the processor, second history information indicating a history of updates based on the received request; predicting, by the processor, a time taken until completion of restoration using the second history information based on an amount of the second history information; and limiting, by the processor, based on the predicted time, at least part of updates of the first data group during the restoration using the second history information.