Data migration method and system

The invention discloses a data migration method and a data migration system, which are used for carrying out LAS file migration between a first machine room and a second machine room, and the method comprises the following steps: calculating a hash value of an LAS file to be migrated in the first machine room; sending the hash value to the second machine room; receiving a Hash value comparison result returned from the second machine room; when the hash value comparison result shows that the LAS file to be migrated does not exist in the second machine room, converting the LAS file to be migrated into a corresponding CAS file; and at least sending the corresponding CAS file to the second machine room. According to the embodiment of the invention, the transmission side converts the file before transmitting the file data, the LAS file is changed into the CAS file, redundancy is removed, the data migration efficiency is improved, and the disk space is also saved. 本发明公开种数据迁移方法及系统，用于在第机房与第二机房之间进行LAS文件的迁移，其中方法包括：计算所述