Patent ID: 8170990
Filing Date: 2012-05-01
Classification: G06F,H04L

Abstract:
1. An information system comprising: a first storage site having a first storage system in communication with a second storage system, the first storage system providing an upper tier of storage having first storage characteristics and the second storage system providing a lower tier of storage having second storage characteristics; a second storage site remote from the first storage site having a third storage system configured to receive remote replication from the first storage system and having a fourth storage system configured to receive remote replication from the second storage system, wherein, when a first file on the first storage system is migrated to the second storage system, a second file is created on the first storage system and stored in place of the first file indicating a storage location of the first file on the second storage system, and wherein, when a copy of the second file is replicated from the first storage system to the third storage system and a copy of the first file is replicated from the second storage system to the fourth storage system via remote replication, information is transmitted to the second storage site for linking the copy of the second file at the third storage system to the copy of the first file at the fourth storage system; a first remote copy module located on the first storage system for carrying out the remote replication from the first storage system to the third storage system; and a second remote copy module located on the second storage system for carrying out the remote replication from the second storage system to the fourth storage system, wherein the second remote copy module checks completion of the replication of the copy of the first file to the fourth storage system, when the replication of the copy of the first file to the fourth storage system is not complete, linking of the copy of the second file at the third storage system to the copy of the first file at the fourth storage system is delayed, and an original target location information is retained, when the replication of the copy of the first file to the fourth storage system is completed, the linking of the copy of the second file at the third storage system to the copy of the first file at the fourth storage system is carried out.