Replication of remote copy data for internet protocol (IP) transmission

• US 7,546,364 B2
• Filed: 05/16/2002
• Issued: 06/09/2009
• Est. Priority Date: 05/16/2002
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Angelone, Raymond A., Vahalia, Uresh, Bergant, Milena, Bono, Jean-Pierre, Gupta, Uday K., Armangau, Philippe, Raman, Suchitra
• Primary Examiner(s): Follansbee; John
• Assistant Examiner(s): Tang; Karen C
• Application Number:
  US10/147,751
• Publication Number:
  US 20030217119A1
• Time in Patent Office: 2,581 Days
• Field of Search: 719/331, 719/321, 719/329, 709/227, 709/201, 709/224, 709/216, 395/825, 370/389, 707/204
• US Class Current: 709/224
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

Consistent updates are made automatically over a wide-area IP network, concurrently with read-only access to the remote copies. A replication control protocol (RCP) is layered over TCP/IP providing the capability for a remote site to replicate and rebroadcast blocks of the remote copy data to specified groups of destinations, as configured in a routing table. A volume multicast layer over RCP provides for multicasting to specified volume extents of the blocks. The blocks are copied at the logical level, so that it does not matter what physical structure is used for storing the remote copies. Save volumes buffer the remote copy data transmitted between the primary or secondary file system volume and the IP network, in order to ensure independence between the replication process, the IP transport method, and the primary file system being replicated.

Claims

1. In a data processing system having a plurality of host computers linked by an Internet Protocol (IP) network to a plurality of data storage systems, each of the data storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, a method of distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers, wherein the method comprises:

the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein the primary data mover computer manages a primary file system in the data storage of the storage system including the primary data mover computer, each secondary data mover computer manages a secondary file system in the data storage of the data storage system including said each secondary data mover computer, and each secondary file system is maintained as a remote copy of the primary file system; and

which includes operating a replication service that transmits modifications of the primary file system to the secondary data mover computers, and then creating a new secondary file system by copying the primary file system to the new secondary file system concurrent with the operation of the replication service, and after the primary file system has been copied to the new secondary file system, updating the new secondary file system with modifications transmitted by the replication service from the primary file system;

wherein the replication service transmits modifications from the primary file system to a save volume during the copying of the primary file system to the new secondary file system, and upon completion of the copying of the primary file system to the new secondary file system, the modifications are copied from the save volume to the new secondary file system; and

wherein the new secondary file system is at a remote site and the save volume is at the remote site, and the method includes transmitting at least a portion of the modifications of the primary file system to the save volume concurrently with the copying of the primary file system to the new secondary file system.

2. In a data processing system having a plurality of host computers linked by an Internet Protocol (IP) network to a plurality of data storage systems, each of the data storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, a method of distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers, wherein the method comprises:

the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein the primary data mover computer manages a primary file system in the data storage of the storage system including the primary data mover computer, each secondary data mover computer manages a secondary file system in the data storage of the data storage system including said each secondary data mover computer, and each secondary file system is maintained as a remote copy of the primary file system; and

wherein the remote copy is a copy by extent, so that there is not a remote copy of data blocks that are not used in the primary file system.

3. The method as claimed in claim 2, wherein the data blocks are remote copied at a logical level, so that it does not matter what physical structure is used for storing the data blocks in the secondary file systems.

4. The method as claimed in claim 2, wherein the primary data mover computer repetitively identifies a next valid block in a volume of the primary file system and identifies a number of valid contiguous blocks following the next valid block in the volume of the primary file system and transmits the next valid block and the number of valid contiguous blocks to said each secondary data mover computer.

5. In a data processing system having a plurality of host computers linked by an Internet Protocol (IP) network to a plurality of data storage systems, each of the data storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, a method of distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers, wherein the method comprises:

the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein only one TCP port to the IP network is used in the forwarder data mover computer for receiving and transmitting the remote copy data to and from the network, and the one TCP port is shared with HTTP connections.

6. In a data processing system having a plurality of host computers linked by an Internet Protocol (IP) network to a plurality of data storage systems, each of the data storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, a method of distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers, wherein the method comprises:

the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein a TCP port to the IP network is used in the forwarder data mover computer for receiving the remote copy data from the network, the TCP port is shared with HTTP connections, a level 5 filter in the forwarder data mover computer passes IP packets of HTTP connections from the TCP port to an HTTP collector service in the forwarder data mover computer, and the level 5 filter passes IP packets of the remote copy data from the TCP port to a replication collector service in the forwarder data mover computer.

7. A data processing system comprising:

a plurality of data storage systems linked by an Internet Protocol (IP) network for access by a plurality of host computers, each of the storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, the data mover computers including means for distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers by the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein the primary data mover computer includes means for managing a primary file system in the data storage of the storage system including the primary data mover computer, and each secondary data mover computer includes means for managing a secondary file system in the data storage of the data storage system including said each secondary data mover computer by maintaining each secondary file system as a remote copy of the primary file system;

which includes a replication service for transmitting modifications of the primary file system to the secondary data mover computers, and means for creating a new secondary file system by copying the primary file system to the new secondary file system concurrent with the operation of the replication service, and after the primary file system has been copied to the new secondary file system, updating the new secondary file system with modifications transmitted by the replication service from the primary file system;

wherein the replication service transmits modifications from the primary file system to a save volume during the copying of the primary file system to the new secondary file system, and upon completion of the copying of the primary file system to the new secondary file system, the modifications are copied from the save volume to the new secondary file system; and

wherein the new secondary file system is at a remote site and the save volume is at the remote site, and the replication service transmits at least a portion of the modifications of the primary file system to the save volume concurrently with the copying of the primary file system to the new secondary file system.

8. A data processing system comprising:

a plurality of data storage systems linked by an Internet Protocol (IP) network for access by a plurality of host computers, each of the storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, the data mover computers including means for distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers by the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein the primary data mover computer includes means for managing a primary file system in the data storage of the storage system including the primary data mover computer, and each secondary data mover computer includes means for managing a secondary file system in the data storage of the data storage system including said each secondary data mover computer by maintaining each secondary file system as a remote copy of the primary file system;

wherein the remote copy is a copy by extent, so that there is not a remote copy of data blocks that are not used in the primary file system.

9. The data processing system as claimed in claim 8, wherein the data blocks are remote copied at a logical level, so that it does not matter what physical structure is used for storing the data blocks in the secondary file systems.

10. The data processing system as claimed in claim 8, wherein the primary data mover computer is programmed to repetitively identify a next valid block in a volume of the primary file system and identify a number of valid contiguous blocks following the next valid block in the volume of the primary file system and transmit the next valid block and the number of valid contiguous blocks to said each secondary data mover computer.

11. A data processing system comprising:

a plurality of data storage systems linked by an Internet Protocol (IP) network for access by a plurality of host computers, each of the storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, the data mover computers including means for distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers by the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein the forwarder data mover computer includes only one TCP port to the IP network for receiving and transmitting the remote copy data to and from the network, the one TCP port also servicing HTTP connections.

12. A data processing system comprising:

a plurality of data storage systems linked by an Internet Protocol (IP) network for access by a plurality of host computers, each of the storage systems having data storage and at least one data mover computer for moving data between the data storage and the IP network, the data mover computers including means for distributing remote copy data over the IP network from a primary one of the data mover computers to a plurality of secondary ones of the data mover computers by the primary data mover computer sending the remote copy data over the IP network to at least one forwarder data mover computer, and the forwarder data mover computer routing the remote copy data over the IP network to the plurality of secondary data mover computers;

wherein the forwarder data mover computer further includes an HTTP collector service, a replication collector service, a TCP port to the IP network for receiving IP packets of the remote copy data from the network and for receiving IP packets of HTTP connections, and a level 5 filter for passing the IP packets of the HTTP connections from the TCP port to the HTTP collector service and passing the IP packets of the remote copy data from the TCP port to the replication collector service.