Pattern-based mapping for storage space management
View Patent ↗In an embodiment of the invention, an apparatus and method for storage space management performs the steps including: activating a logical volume group; reading pattern-based mapping information from physical volumes in the logical volume group; and using the pattern-based mapping information to determine a target physical extent in at least one of the physical volumes for a received request.
1. A method for storage space management, the method comprising:
activating a logical volume group;
reading a mapping formula from physical volumes in the logical volume group; and
using a mapping formula to determine a target physical extent in at least one of the physical volumes for a received request;
wherein the mapping formula is based on a number of extents in a logical volume, a physical volume, and a starting offset of a physical extent in the physical volume.
2. The method of claim 1 , wherein the mapping formula maps a logical volume to a physical volume.
3. The method of claim 2 , wherein the mapping formula maps logical extents in the logical volume to physical extents in the physical volume.
4. The method of claim 1 , further comprising: storing the mapping formula in a host memory.
5. The method of claim 4 , further comprising: using the mapping formula to determine the target physical extent for the request.
6. The method of claim 1 , further comprising: storing the mapping formula into the physical extents.
7. The method of claim 1 , wherein the mapping formula indicates at least one of: a number of extents in a logical volume, at least one physical volume, and a starting offset of a physical extent in the physical volume.
8. The method of claim 1 , wherein the mapping formula permits an increase in a data structure size to be stored in meta-data regions in the physical volumes.
9. An apparatus for storage space management, the apparatus comprising: a volume manager configured to activate a logical volume group, read a mapping formula that translates from physical volumes in the logical volume group, and use the mapping formula to determine a target physical extent in at least one of the physical volumes for a received request;
wherein the mapping formula is based on a number of extents in a logical volume, a physical volume, and a starting offset of a physical extent in the physical volume.
10. The apparatus of claim 9 , wherein the mapping formula maps a logical volume to a physical volume.
11. The apparatus of claim 10 , wherein the mapping formula maps logical extents in the logical volume to physical extents in the physical volume.
12. The apparatus of claim 9 , wherein the volume manager is configured to store the mapping formula in a host memory.
13. The apparatus of claim 12 , wherein the volume manager is configured to use the mapping formula to determine the target physical extent for the request.
14. The apparatus of claim 9 , wherein the volume manager is configured to store the mapping formula into the physical extents.
15. The apparatus of claim 9 , wherein a mapping formula indicates at least one selected from the group consisting of: a number of extents in a logical volume, at least one physical volume, and a starting offset of a physical extent in the physical volume.
16. The apparatus of claim 9 , wherein the mapping formula permits an increase in a data structure size to be stored in meta-data regions in the physical volumes.
17. An article of manufacture, comprising:
a non-transitory machine-readable medium having stored thereon instructions to:
activate a logical volume group;
read a mapping formula from physical volumes in the logical volume group; and
use the mapping formula to determine a target physical extent in at least one of the physical volumes for a received request;
wherein the mapping formula is based on a number of extents in a logical volume, a physical volume, and a starting offset of a physical extent in the physical volume.