Methods and systems for preserving disk geometry of virtualized data volumes
Methods and systems for preserving disk geometry when relabeling a data volume encapsulated in a virtual storage device that presents a different disk geometry than the data volume. An exemplary method includes maintaining information from a label of the data volume in a memory associated with the virtual storage device and intercepting a request for information related to a disk geometry of the encapsulated data volume that is normally answered without reference to the label. The request may be associated with a command to relabel the encapsulated data volume. The method also includes reporting the information from the label of the data volume related to the disk geometry of the data volume if the label is associated with an operating system that considers a geometry of a data volume when partitioning.
1. A method for preserving disk geometry when relabeling a data volume encapsulated in a virtual storage device that presents a different disk geometry than the data volume, the method comprising:
maintaining information from a label of the data volume in a memory associated with the virtual storage device;
intercepting a request for information related to a disk geometry of the encapsulated data volume that is normally answered without reference to the label; and
if the label is associated with an operating system that considers a geometry of a data volume when partitioning, reporting information from the label of the data volume in response to the request.
2. The method of claim 1 further comprising storing information from the label of the data volume in a memory associated with the virtual storage device when the data volume is encapsulated in the virtual storage device.
3. The method of claim 1 wherein the memory associated with the virtual storage device comprises a disk array for storing metadata related to at least one data volume.
4. The method of claim 1 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Mode Sense 3 SCSI command.
5. The method of claim 4 wherein reporting information from the label of the data volume in response to the request comprises reporting a number of sectors in a head and a number of heads in a cylinder of the data volume.
6. The method of claim 1 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Mode Sense 4 SCSI command.
7. The method of claim 6 wherein reporting information from the label of the data volume in response to the request comprises reporting a number of cylinders in the data volume.
8. The method of claim 1 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Read Capacity 3 SCSI command.
9. A system for preserving disk geometry when relabeling a data volume encapsulated in a virtual storage device that presents a different disk geometry than the data volume, the system comprising:
an intelligent multi-protocol switch (IMPS);
a memory for storing metadata related to at least one data volume; and
a controller coupled to the IMPS and the memory, wherein the controller comprises a processor configured to manage the at least one data volume using the metadata and the IMPS, and wherein the controller is configured to implement a method for preserving disk geometry when relabeling a physical device encapsulated in a virtual storage device that presents a different disk geometry, the method comprising:
maintaining information from a label of the data volume in a memory associated with the virtual storage device;
intercepting a request for information related to a disk geometry of the encapsulated data volume that is normally answered without reference to the label; and
if the label is associated with an operating system that considers a geometry of a data volume when partitioning, reporting information from the label of the data volume in response to the request.
10. The system of claim 9 wherein the method further comprises storing information from the label of the data volume in the memory coupled to the controller when the data volume is encapsulated the virtual storage device.
11. The system of claim 9 wherein the memory coupled to the controller comprises a disk array for storing metadata related to at least one data volume.
12. The system of claim 9 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Mode Sense 3 SCSI command and wherein reporting information from the label of the data volume comprises reporting a number of sectors in a head and a number of heads in a cylinder of the data volume.
13. The system of claim 9 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Mode Sense 4 SCSI command and wherein reporting information from the label of the data volume comprises reporting a number of cylinders in the data volume.
14. The system of claim 9 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Read Capacity SCSI command.
15. A computer-readable medium comprising programmable instructions adapted to perform a computer-implemented method for preserving disk geometry when relabeling a data volume encapsulated in a virtual storage device that presents a different disk geometry than the data volume, the method comprising:
maintaining information from a label of the data volume in a memory associated with the virtual storage device;
intercepting a request for information related to a disk geometry of the encapsulated data volume that is normally answered without reference to the label; and
if the label is associated with an operating system that considers a geometry of a data volume when partitioning, reporting information from the label of the data volume in response to the request.
16. The medium of claim 15 wherein the method further comprises storing information from a label of the data volume in a memory coupled to the virtual storage device when the data volume is encapsulated in the virtual storage device.
17. The medium of claim 16 wherein the memory coupled to the virtual storage device comprises a disk array for storing metadata related to at least one data volume.
18. The medium of claim 15 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Mode Sense 3 SCSI command and wherein reporting information from the label of the data volume comprises reporting a number of sectors in a head and a number of heads in a cylinder of the data volume.
19. The medium of claim 15 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Mode Sense 4 SCSI command and wherein reporting information from the label of the data volume comprises reporting a number of cylinders in the data volume.
20. The medium of claim 15 wherein the request for information related to a disk geometry of the encapsulated data volume comprises a Read Capacity SCSI command.