Claims
- 1. A method for moving information from a first physical storage location to a second physical storage location in a virtual storage system for linking a host to the storage locations, the system having an agent connected to the host, the agent storing a table, the table having entries that map to virtual storage disk positions to the locations on the storage devices, the table entries including an indication of whether a no-write (Nw) state is activated, whereby activation of the Nw state prevents writing operations to the storage location contained in that entry, and a controller connected to the agent, the controller controlling the contents of the table, the method comprising the steps of:
a) the controller activating the Nw state for the table entry corresponding to the first physical storage location; b) copying information from the first physical storage location to the second physical storage location; c) the controller changing the virtual mapping from the first physical location to the second physical location; and d) the controller deactivating the Nw state for the table entry corresponding to the second physical storage location.
- 2. A virtual storage system for moving data accessed over a network from a first storage location to a second storage location on a storage device, the system comprising:
an agent having volatile memory for storing a first copy of a table, the table having entries to map virtual disk positions to locations on the storage device; and a controller coupled to the agent, the controller having non-volatile memory for storing a second copy of the table and means for directing movement of data from the first storage location to the second storage location while the agent prevents any I/O operations that would change the data at the first storage location.
- 3. The system of claim 2, wherein said agent includes means for updating the first copy of the table in response to direction from the controller to match an updated copy of the second copy of the table.
- 4. The system of claim 2, wherein the table entries further include an indication of whether an invalid state is activated such that the invalid state for a table entry becomes activated when that table entry contains no useable mapping information.
- 5. The system of claim 4, wherein the agent does not allow the host to complete the I/O operations with one of the entries if the invalid state for that entry is activated.
- 6. The system of claim 2, wherein the table entries further include an indication of whether a Nw state is activated such that the Nw state for one of the entries becomes activated when data cannot be written to the storage location contained in that entry.
- 7. The system of claim 6, wherein the agent does not allow the host to write data to the storage location in one of the entries if the no-write state for that entry is activated.
- 8. The system of claim 2, further comprising a communication channel to couple the agent and the controller.
- 9. The system of claim 8, wherein the communication channel employs a data transfer protocol to transport messages on the communication channel.
- 10. The system of claim 2, wherein the entries include an offset.
- 11. The system of claim 10, wherein the offset includes a logic unit number identifier.
- 12. The system of claim 10, wherein the offset includes a block identifier.
- 13. A method for maintaining a table for mapping virtual disk blocks to migrated storage locations on storage devices within a network, comprising:
activating states within entries of the table; migrating data from a first storage location to a second storage location; completing operations at the table; and updating the table in response to the command.
- 14. The method of claim 13, further comprising setting a blocking flag until operations are completed.
- 15. The method of claim 13, further comprising obtaining mapping information from one of the entries in the table.
- 16. A method for moving data from a first storage location to a second storage location on a storage device in a virtual disk storage system, comprising:
providing an agent having volatile memory for storing a first copy of a table, the table having entries to map virtual disk positions to locations on the storage device; providing a controller coupled to the agent, the controller having non-volatile memory for storing a second copy of the table; responsive to a request to move virtual disk data from a first location to a second location, the controller changing the second copy of the table and issuing an order to change the first copy of the table to the agent; after completion of all prior I/O operations, the agent alerting the controller of completion; the controller then copying the contents of the first storage location to the second storage location; the controller then updating the second copy of the table and directing the agent to update the first copy of the table to match the updated second copy of the table; and after completion of all prior I/O operations, the agent updating the first copy of the table to match the updated second copy of the table and responding to the controller.
RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Application Nos. 60/209,109 and 60/209,326, filed on Jun. 2, 2000, the disclosures of which are hereby incorporated by reference in full.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60209109 |
Jun 2000 |
US |
|
60209326 |
Jun 2000 |
US |