Patent ID: 7653671
Filing Date: 2010-01-26
Classification: G06F,H04L,Y10S

Abstract:
1. A file management method in a storage system having a first network segment and a second network segment that are connected to each other, wherein the first network segment includes: a first disk apparatus storing a first file, a first management server having a first file table managing a storage location and a retention period of the first file stored on the first disk apparatus, and a first time server providing first time information to the first management server, wherein the second network segment includes: a second disk apparatus storing a second file corresponding to the first file and having the same content as that of the first file stored on the first disk apparatus, a second management server storing a second file table managing a storage location and a retention period of the second file stored on the second disk apparatus, and a second time server, independent of the first time server, providing second time information to the second management server, said file management method comprising: obtaining, by the first management server, the storage location of the second file which corresponds to the first file when the first time information indicates that the retention period of the first file has expired based on the first time information, sending a query from the first management server to the second management server defined as the obtained storage location of the second file to determine whether the retention period of the second file has expired; referring, by the second management server, to the second file table and the second time information, and sending a response to the first management server indicating whether the retention period of the second file has expired based on the second time information; receiving the response by the first system management server; generating, by the first management server, a notification that deletion of the first file from the first disk apparatus is not permitted when the response indicates that the retention period of the second file has not yet expired; flagging the first file for deletion from the first disk apparatus, by the first management server, when the response indicates that the retention period of the second file has expired also on the second disk apparatus; obtaining, by the second management server, the storage location of the first file which corresponds to the second file when the second time information indicates that the retention period of the second file has expired based on the second time information, sending a query from the second management server to the first management server defined as the obtained storage location of the first file to determine whether the retention period of the first file has expired; referring, by the first management server, to the first file table and the first time information, and sending a response to the second management server indicating whether the retention period of the first file has expired based on the first time information; receiving the response by the second management server; generating, by the second management server, a notification that deletion of the second file from the second disk apparatus is not permitted when the response indicates that the retention period of the first file has not yet expired; and flagging the second file for deletion from the second disk apparatus, by the second management server, when the response indicates that the retention period of the first file has expired also on the first disk apparatus.