Method and system for providing virtualization data services for legacy storage devices

• US 7,363,457 B1
• Filed: 07/21/2005
• Issued: 04/22/2008
• Est. Priority Date: 07/21/2005
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Blount, Joseph, Vetter, Mark S., Dekoning, Rodney A., Proulx, Ronald D., Kopper, David A.
• Primary Examiner(s): ELMORE, STEPHEN C
• Application Number:
  US11/186,226
• Time in Patent Office: 1,006 Days
• Field of Search: 711/170, 711/203, 711/6, 711/112, 711/114
• US Class Current: 711/170
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A method, and associated system, for delivering data services such as virtualization to legacy devices. The method involves reserving a metadata region in memory of a storage resource in a storage pool that is controlled by (or is captive to) a data services platform. The metadata region includes a global set containing information used by the data services platform to manage the data services, including virtualization of volumes throughout the storage pool. The method includes locating an available legacy storage device and retrieving element information for the legacy storage device. A volume or virtualized legacy volume is built based on the collected element information, and the global set in the metadata region is update to include volume information for the legacy storage device. The legacy storage device includes memory that stores legacy or user data, but the steps of the method are performed to leave the legacy data unchanged.

Claims

1. A method for providing data services such as virtualization to legacy storage devices, comprising:

reserving a metadata region in memory of each storage resource that is provided in a storage pool and that is controlled by a data services platform, the metadata region including a global set of data containing information used by the data services platform to manage the data services including virtualization of volumes throughout the storage pool;

locating a legacy storage device available for inclusion in the storage pool;

retrieving element information for the legacy storage device;

building a virtualized legacy volume based on the element information; and

updating the global set of data in the metadata region to include information on the virtualized legacy volume built using the legacy storage device element information wherein the legacy storage device comprises memory storing legacy data and wherein the legacy data is unchanged by completion of the reserving, the locating, the retrieving, the building, and the updating.

2. The method of claim 1, wherein the element information includes extent and disk information for the legacy storage device.

3. The method of claim 1, wherein the building of the volume for the legacy storage device comprises building a volume tree and marking the volume tree as the virtualized legacy volume.

4. The method of claim 1, further comprising providing a snapshot storage resource for the built volume including updating a metadata region of the snapshot storage resource based on the volume information for the legacy storage device.

5. The method of claim 1, further comprising providing a symmetric multi-path to the legacy storage device using the built volume.

6. The method of claim 1, further comprising rebooting the data services platform after the updating of the global set of data, the rebooting including building a volume tree image for each storage resource in the storage pool including the legacy storage device for which the volume tree image is built from the volume information for the legacy storage device stored in the global set of data in the metadata region of the memory in the data services platform-controlled storage resource.

7. A data storage system adapted for providing virtualization services to captive and legacy storage devices without destroying stored legacy data, comprising:

a storage controller;

a plurality of storage resources linked to the storage controller and captive to the storage controller, each of the captive storage resources comprising memory with a configuration metadata region storing data specific to the particular storage resource that is used by the storage controller to provide the virtualization services to the particular storage resource;

a legacy storage device storing a set of legacy data; and

a subset of the storage resources storing a global set of data used by the storage controller in providing the virtualization services to the storage resources, wherein the global set of data further comprises volume data for a virtualized volume for the legacy storage device used by the storage controller in providing the virtualization services to the legacy storage device.

8. The system of claim 7, wherein the legacy storage device is a disk device and wherein the volume data for the legacy storage device comprises extent and disk information.

9. The system of claim 8, wherein one of storage resources is configured and maintained as a snapshot of the virtualized volume of the legacy storage device.

10. The system of claim 7, further comprising a database storing volume trees for the plurality of storage resources and for the legacy storage device.

11. A virtualization method for use in providing virtualization services to legacy storage devices made available in a storage resource pool, comprising:

locating attached logical units in a data storage pool controlled by a storage controller, wherein the located attached logical units comprise a legacy storage device;

generating a request to build a volume for the legacy storage device;

retrieving element information for the legacy storage device;

building a volume tree for the legacy storage device based on the element information; and

based on the volume tree, storing virtualized legacy volume data for the legacy storage device in a metadata region on one of the located attached logical units other than the legacy storage device.

12. The method of claim 11, wherein the element information comprises extent and volume information for the legacy storage device.

13. The method of claim 11, further comprising storing the virtualized legacy volume data in a metadata region on a second one of the located attached logical units.

14. The method of claim 11, further comprising designating one of the located attached logical units as a snapshot device for the built volume including updating a metadata region of the snapshot device based on the volume information for the legacy storage device.

15. The method of claim 11, further comprising providing a symmetric multi-path to the legacy storage device using the virtualized legacy volume.

16. The method of claim 11, further comprising rebooting the storage controller after the storing of the virtualized legacy volume, the rebooting including building a volume tree image for each attached logical unit in the storage pool including the legacy storage device for which the volume tree image is built from the virtualized legacy volume data.

17. The method of claim 11, wherein the attached logical units other than the legacy storage device are captive to the storage controller.