Replication and restoration of multiple data storage object types in a data network

• US 7,769,722 B1
• Filed: 12/08/2006
• Issued: 08/03/2010
• Est. Priority Date: 12/08/2006
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Zhu, Daniel, Pasula Reddy, Santosh, Tummala, Himabindu, Bergant, Milena, Hayden, John M.
• Primary Examiner(s): Jalil; Neveen Abel
• Assistant Examiner(s): KINSAUL, DANIEL W
• Time in patent office: 1334 Days
• Field of Search: None
• US Class Current: 707/681
• CPC Class Codes: G06F 11/006 Identification G06F11/2289 takes precedence
• CPC Class Codes: G06F 11/2028 eliminating a faulty processor or activating a spare
• CPC Class Codes: G06F 11/2038 with a single idle spare processing component
• CPC Class Codes: G06F 11/2041 with more than one idle spare processing component
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/125 characterised by the use of retention policies retention policies for HSM systems G06F16/185
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/184 implemented as replicated file system

Abstract

A data storage server is programmed for management, version control, and scheduling of replication of multiple types of data storage objects including iSCSI LUNs and file systems. The version control determines if two data storage objects are the same or have a common base so that only a difference needs to be transmitted for replication or restoration. A replication job may specify a “one-to-many” replication or a cascaded replication, and any snapshot retention policy is propagated during a cascaded replication. Concurrent replication sessions to the same destination are paced in accordance with respective allocation shares of the reception bandwidth. File handle information is replicated so that a file handle issued by a primary data storage server can be used for accessing a replicated file in a secondary data storage server.

Claims

1. A method of restoring, in a first data storage server, a data storage object from a desired version of the data storage object, the desired version of the data storage object residing in data storage of a second data storage server, said method comprising:

the first data storage server communicating with the second data storage server to identify a most recent common base snapshot copy of the data storage object, a first copy of the most recent common base snapshot copy residing in data storage of the first data storage server and a second copy of the most recent common base snapshot copy residing in the data storage of the second data storage server; and

the second data storage server transmitting to the first data storage server changes between the desired version of the data storage object and the second copy of the most recent common base snapshot copy; and

the first data storage server receiving the changes from the second data storage server and using the changes for restoring, from the first copy of the most recent common base snapshot copy, a local production version of the data storage object;

wherein said method is used for restoring, in the first data storage server an iSCSI LUN data storage object from a desired version of the iSCSI LUN data storage object, the desired version of the iSCSI LUN data storage object residing in the data storage of the second data storage server,

wherein said method is used for restoring in the first data storage server, a file system data storage object from a desired version of the file system data storage object, the desired version of the file system data storage object residing in the data storage of the second data storage server, and

which further includes the first data storage server initially receiving the first copy of the most recent common base snapshot copy remote replication from a third data storage server, and the second data storage server initially receiving the second copy of the most recent common base snapshot copy by remote replication from the third data storage server, and

which includes specifying a retention policy for snapshot copies in the third data storage server, and wherein the remote replication from the third data storage server includes the third data storage server replicating the retention policy for snapshot copies to the first data storage server and to the second data storage server.

2. A method of restoring, in a first data storage server, a data storage object from a desired version of the data storage object, the desired version of the data storage object residing in data storage of a second data storage server, said method comprising:

the first data storage server communicating with the second data storage server to identify a most recent common base snapshot copy of the data storage object, a first copy of the most recent common base snapshot copy residing in data storage of the first data storage server and a second copy of the most recent common base snapshot copy residing in the data storage of the second data storage server; and

the second data storage server transmitting to the first data storage server changes between the desired version of the data storage object and the second copy of the most recent common base snapshot copy; and

the first data storage server receiving the changes from the second data storage server and using the changes for restoring, from the first copy of the most recent common base snapshot copy, a local production version of the data storage object

wherein said method is used for restoring in the first data storage server an iSCSI LUN data storage object from a desired version of the iSCSI LUN data storage object, the desired version of the iSCSI LUN data storage object residing in the data storage of the second data storage server,

wherein said method is used for restoring in the first data storage server, a file system data storage object from a desired version of the file system data storage object, the desired version of the file system data storage object residing in the data storage of the second data storage server, and

which further includes the first data storage server initially receiving the first copy of the most recent common base snapshot copy remote replication from a third data storage server and the second data storage server initially receiving the second copy of the most recent common base snapshot copy by remote replication from the third data storage server, and

wherein the remote replication from the third data storage server to the first data storage server includes replicating file handle information from the third data storage server to the first data storage server, and wherein said method further includes the third data storage server issuing a file handle to a network client accessing the file system data storage object, and the network client using the file handle in a read-write request sent to the first data storage server, and the first data storage server receiving the file handle and using the file handle information replicated from the third data storage system for accessing a production version of the file system data storage object in said first data storage server.