Patent ID: 8521693

Claim:
A storage system comprising: a plurality of first file storage apparatuses including a first storage apparatus having a plurality of first volumes constituting a logical storage area of a first storage device, and a first controller for controlling data input/output processing on a plurality of first file systems constructed on the first volumes of the first storage apparatus; and a second file storage apparatus connected to the first file storage apparatus via a first network, the second file storage apparatus including a second storage apparatus having a plurality of second volumes constituting a logical storage area of a second storage device, and a second controller for controlling data input/output processing on a plurality of second file systems constructed on the second volumes of the second storage apparatus; wherein the first controller includes a first pre-migration processor for generating a first migration task list that associates and records information about scheduled time periods for execution of a first migration from the first file systems to the second file systems and a total file size of files, which are targets of the first migration, with a file system which is a first migration destination, and then transferring the generated first migration task list to the second file storage apparatus before execution of the first migration; wherein the second controller includes a second pre-migration processor for generating, based on the first migration task list transferred from the first pre-migration processor, a second migration overlap table that records, for each unit time, whether the execution of the first migration is scheduled or not for each of the file systems which are a first migration sources whose at least part of the scheduled time periods for the execution of the first migration overlaps with each other; and generating, based on the generated second migration overlap table, a second remaining file size table that records, for each of the file systems which are the first migration sources, a predicted value of a data transfer amount per unit time and a predicted value of a remaining file size per unit time; and wherein the second pre-migration processor predicts, based on the generated second remaining file size table, whether the first migration will be executed successfully or not.