Method and apparatus for accessing a virtualized storage volume using a pre-loaded volume map
A method and apparatus for accessing a virtualized storage volume are described. At least one volume map is copied to a virtualization switch prior to an application requesting access to a storage volume via the virtualization switch, where the volume map facilitates mapping the storage volume access request to an appropriate physical storage device and is copied from a source external to the virtualization switch.
1. A method for accessing a virtualized storage volume comprising:
providing an access pattern for accessing information on at least one virtual storage volume;
prior to a storage volume access request by an application requesting access to a storage volume via a virtualization switch, copying an initial portion of a volume map to the virtualization switch to facilitate mapping the storage volume access request to an appropriate physical storage device of the at least one virtual storage volume, wherein the initial portion of the volume map is copied from an entity external to the virtualization switch based upon the access pattern; and
after one or more additional storage volume access requests by the application requesting access to the storage volume via the virtualization switch, replacing the initial portion of the volume map with an additional portion of the volume map at the virtualization switch, wherein the additional portion of the volume map is copied from the entity external to the virtualization switch based upon the access pattern.
2. The method of claim 1 wherein the virtualization switch comprises a memory for temporarily storing the at least one volume map.
3. The method of claim 2 wherein the memory is coupled to a data path processor.
4. The method of claim 3 wherein the data port processor is coupled to a control path processor.
5. The method of claim 4 wherein the initial portion of the volume map is requested by the control path processor.
6. The method of claim 1 wherein the entity is a SAN volume server.
7. The method of claim 1 wherein the specific application is either an antivirus application or a backup application.
8. The method of claim 1 wherein the volume map is used to map the storage volume access request to an appropriate storage volume of the at least one virtual storage volume.
9. The method of claim 1 further comprising copying at least one extent map to the virtualization switch to facilitate using complex storage attributes for different regions within the virtualized LUN.
10. An apparatus for accessing a virtualized storage volume comprising:
means for providing an access pattern for accessing information on at least one virtual storage volume;
means for copying, prior to a storage volume access request by an application requesting access to a storage volume via a virtualization switch, an initial portion of a volume map to the virtualization switch to facilitate mapping the storage volume access request to an appropriate physical storage device of the at least one virtual storage volume, wherein the initial portion of the volume map is copied from an entity external to the virtualization switch based upon the access pattern; and
means for replacing, after one or more additional storage volume access requests by the application requesting access to the storage volume via the virtualization switch, the initial portion of the volume map with an additional portion of the volume map at the virtualization switch, wherein the additional portion of the volume map is copied from the entity external to the virtualization switch based upon the access pattern.
11. The apparatus of claim 10 wherein the virtualization switch further comprises a memory for temporarily storing the at least one volume map.
12. The apparatus of claim 11 wherein the memory is coupled to a data path processor.
13. The apparatus of claim 12 wherein the data path processor is coupled to a control path processor.
14. The apparatus of claim 13 wherein the initial portion of the volume map is requested by the control path processor.
15. The apparatus of claim 10 wherein the entity is a SAN volume server.
16. The apparatus of claim 10 wherein the specific application is either an antivirus application or a backup application whose access pattern is well known even before the application starts.
17. A system for accessing a virtualized storage volume comprising:
a virtualization switch for mapping an access request to at least one virtual storage volume;
a SAN volume server for managing the at least one virtual storage volume and storing at least one volume map and at least one extent map; and
a processor configured to execute pre-loading software for providing an access pattern for accessing information on the at least one virtual storage volume and copying an initial portion of the at least one volume map and the at least one extent map to the virtualization switch from the SAN volume server in response to an access request to the at least one virtual storage volume from an application, wherein the copying the initial portion of the at least one volume map and the at least one extent map is based on the access pattern; and further configured to after one or more additional storage volume access requests by the application requesting access to the storage volume via the virtualization switch, replacing the initial portion of the at least one volume map with an additional portion of the at least one volume map at the virtualization switch, wherein the additional portion of the at least one volume map is copied from the entity external to the virtualization switch based upon the access pattern.
18. The system of claim 17 further comprising a client computer for executing the application, wherein the application requests access to the at least one virtual storage volume via the virtualization switch.