On-line data migration of a logical/virtual storage array

• US 7,697,515 B2
• Filed: 12/27/2005
• Issued: 04/13/2010
• Est. Priority Date: 12/27/2005
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Ofer, Adi, Madnani, Kiran, Brown, Jeffrey A.
• Primary Examiner(s): Kumar; Pankaj
• Assistant Examiner(s): SMITH, MARCUS
• Application Number:
  US11/318,719
• Publication Number:
  US 20070263637A1
• Time in Patent Office: 1,568 Days
• Field of Search: 711/5, 711/6, 711/165
• US Class Current: 370/389
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Data is transparently migrated between groups of logical units of storage presented as virtual arrays. A source virtual array has at least one source virtual port coupled to a fabric. Each source virtual port having a source virtual port name and a source virtual port address. A destination virtual array has one or more destination virtual ports coupled to the fabric, each destination virtual port having a destination virtual port name and a destination virtual port address. All data resident on the source virtual array is copied to the destination virtual array. The destination virtual port names and LUN names and numbers are then exchanged with the source virtual port names and LUN names and numbers. The fabric then updates its name server database so that the database associates the source virtual port name with the destination virtual port address.

Claims

1. Apparatus for use in a storage system comprising a Fibre Channel fabric having a database that associates Fibre Channel names and Fibre Channel addresses of Fibre Channel ports coupled to it, the apparatus comprising:

a plurality of groups of logical units of storage;

at least one physical port coupled to the groups through which the groups are coupled to the fabric;

each group assigned a unique virtual port address for each physical port to which it is coupled;

a first said group comprising a source virtual array, the source virtual array having one or more source virtual ports coupled to the fabric, each source virtual port having a source virtual port name and a source virtual port address;

a second said group comprising a destination virtual array, the destination virtual array having one or more destination virtual ports coupled to the fabric, each destination virtual port having a destination virtual port name and a destination virtual port address;

logic for copying all data resident on the source virtual array to the destination virtual array;

logic for exchanging the source virtual port names with the destination virtual port names so that source virtual ports have the destination virtual port names and the destination virtual ports have the source virtual port names;

logic for causing the fabric to reload its name server database so that the database associates the source virtual port names with the destination virtual port addresses and the destination virtual port names with the source virtual port addresses.

2. The apparatus of claim 1 wherein the source virtual array includes source LUNs for use by the host(s), each source LUN having a source LUN name and source LUN number, and wherein the destination virtual array includes destination LUNs for use by the hosts, each destination LUN having a destination LUN name and a destination LUN number, and wherein the logic for exchanging further comprises logic for exchanging the source LUN names with the destination LUN names so that the source LUNs have the destination LUN names and the destination LUNs have the source LUN names, such that the destination LUNs appear to the host(s) as the source LUNs.

3. The apparatus of claim 2 wherein the logic for exchanging further comprises logic for exchanging the source LUN numbers with the destination LUN numbers so that the source LUNs have the destination LUN numbers and the destination LUNs have the source LUN numbers, such that the destination LUNs appear to the host(s) as the source LUNs.

4. The apparatus of claim 3 further comprising source and destination virtual port translation tables respectively;

the source virtual port translation table associating the source virtual port names with the destination virtual port names, the destination virtual translation table associating the destination virtual port names with the source virtual port names,

the translation tables used by the logic for exchanging for exchanging the source and destination virtual port names with the destination and source virtual port names respectively.

5. The apparatus of claim 4 further comprising source and destination LUN translation tables respectively;

the source translation table associating the source LUN names and numbers with the destination LUN names and numbers, the destination translation table associating the destination LUN names and numbers with the source LUN names and numbers;

the translation tables used by the logic for, exchanging for replacing the first and second LUN names and numbers with the second and first LUN names and numbers respectively.

6. The apparatus of claim 5 wherein the logic for exchanging comprises a source array controller capable of enabling the source port and source LUN translation tables, and a destination array controller capable of enabling the destination port and destination LUN translation tables.

7. The apparatus of claim 6 wherein the source array controller and destination ray controller enable the source and destination port translation tables and source and destination LUN translation tables respectively in accordance with a handshake protocol.

8. A program product comprising a non-transitory computer readable medium having embodied therein a computer program for storing data, the computer program for operation in a system including a Fibre Channel fabric having a database that associates Fibre Channel names and Fibre Channel addresses of Fibre Channel ports coupled to it, a plurality of groups of logical units of storage, and at least one physical port coupled to the groups through which the groups can be coupled to the fabric, the program product comprising:

logic for assigning to each group a unique virtual port address for each physical port to which it is coupled, a first said group comprising a source virtual array, the source virtual array having at least one source virtual port coupled to the fabric, each source virtual pert having a source virtual port name and a source virtual port address, a second said group comprising a destination virtual array, the destination virtual array having one or more destination virtual ports coupled to the fabric, each destination virtual port having a destination virtual port name and a destination virtual port address;

logic for copying all data resident on the source virtual array to the destination virtual array;

logic for exchanging the source virtual port names with the destination virtual port names so that the source virtual ports have the destination virtual port names and the destination virtual ports has the source virtual port names;

logic for causing the fabric to reload its name server database so that die database associates the source virtual port names with the destination virtual port addresses and the destination virtual port names with the source virtual port addresses.

9. The program product of claim 8 wherein the source virtual array includes source LUNs for use by the host(s), each source LUN having a source LUN name and source LUN number, and wherein the destination virtual array includes destination LUNs for use by the hosts, each destination LUN having a destination LUN name and a destination LUN number, and wherein:

the logic for exchanging further comprises logic for exchanging the source LUN names with the destination LUN names so that the source LUNs have the destination LUN names and the destination LUNs have the source LUN names, such that the destination LUNs appear to the host(s) as the source LUNs.

10. The program product of claim 9 wherein the logic for exchanging uses a source virtual port translation table associating the source virtual port names with the destination virtual port names, and a destination virtual port translation table associating the destination virtual port names with the source port names, for exchanging the source and destination virtual port names with the destination and source virtual port names respectively.

11. The program product of claim 10 wherein the logic for exchanging uses a source LUN translation table associating the source LUN names and numbers with the destination LUN names and numbers, and a destination LUN translation table associating the destination LUN names and numbers with the source LUN names and numbers, for exchanging the source and destination LUN names with the destination and source LUN names respectively.

12. The program product of claim 11 wherein the logic for exchanging comprises source array controller logic and destination array controller logic, the source array controller logic capable of enabling the source port and source LUN translation tables, the destination array controller logic capable of enabling the destination port and destination LUN translation tables.

13. The program product of claim 12 wherein the source array controller logic and destination array controller logic enable the source and destination port translation tables and source and destination LUN translation tables respectively in accordance with a handshake protocol.

14. A method for operation in a system comprising:

a Fibre Channel fabric having a database that associates Fibre Channel names and Fibre Channel addresses of Fibre Channel ports coupled to it,

a plurality of groups of logical units of storage;

at least one physical port coupled to the groups through which the groups can be coupled to the fabric;

each group assigned a unique virtual port address for each physical port to which it is coupled;

a first said group comprising a source virtual array, the source virtual array having at least one source virtual port coupled to the fabric, each source virtual port having a source virtual port name and a source virtual port address;

a second said group comprising a destination virtual array, the destination virtual array having one or more destination virtual ports coupled to the fabric, each destination virtual port having a destination virtual port name and a destination virtual port address;

the method comprising the steps of;

copying all data resident on the source virtual array to the destination virtual array;

exchanging the source virtual port names with the destination virtual port names so that the source virtual ports have the destination virtual port names and the destination virtual ports have the source virtual port names;

causing the fabric to reload its name server database so that the database associates the source virtual port names with the destination virtual port addresses and the destination virtual port names with the source virtual port addresses.

15. The method of claim 14 wherein the source virtual array includes source LUNs for use by the host(s), each source LUN having a source LUN name and source LUN number, and wherein the destination virtual array includes destination LUNs for use by the hosts, each destination LUN having a destination LUN name and a destination LUN number, and wherein the step of exchanging further comprises the step of:

exchanging the source LUN names wit the destination LUN names so that the source LUNs have the destination LUN names and the destination LUNs have the source LUN names, such that the destination LUNs appear to the host(s) as the source LUNs.

16. The method of claim 15 wherein the step of exchanging further comprises using a source virtual port translation table associating the source virtual port names with the destination virtual port names, and using a destination translation table associating the destination virtual port names with the source virtual port names, for exchanging for replacing the source and destination virtual port names with the destination and source virtual port names respectively.

17. The method of claim 16 wherein the step of exchanging further comprises using a source LUN translation table associating the source LUN names and numbers with the destination LUN names and numbers, and using a destination LUN translation table associating the destination LUN names and numbers with the source LUN names and numbers, for exchanging the source and destination LUN names and numbers with the destination and source LUN names and numbers respectively.

18. The method of claim 17 wherein the step of exchanging further comprises the steps of:

enabling by a source array controller the source port and source LUN translation tables;

enabling by a destination array controller the destination port and destination LUN translation tables.

19. The method of claim 18 wherein the step of enabling by a source array controller and the step of enabling by a destination array controller employs a handshake protocol.