Location-independent RAID group virtual block management

• US 20060271734A1
• Filed: 08/02/2006
• Published: 11/30/2006
• Est. Priority Date: 03/21/2003
• Status: Active Grant

• Current Assignee: Douglas P. Doucette, Scott Schoenthal, Srinivasan Viswanathan, Stephen H. Strange
• Original Assignee: Douglas P. Doucette, Scott Schoenthal, Srinivasan Viswanathan, Stephen H. Strange
• Inventors: Schoenthal, Scott, Doucette, Douglas P., Viswanathan, Srinivasan, Strange, Stephen H.
• Granted Patent: US 7,660,966 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/2056 by mirroring
• CPC Class Codes: G06F 2211/1023 Different size disks, i.e. non uniform size of disks in RAID systems with parity
• 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 3/0643 Management of files
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A storage operating system is configured to assign volume block numbers (VBNs) to a volume. The system has a plurality of disks, and each disk of the plurality of disks is assigned disk block numbers (DBNs). A raidmap is configured to map the VBNs to the DBNs of the plurality of physical disks, the mapping for a particular disk stored in a disk label for the particular disk. The disk label for the particular disk is then written to the particular disk.

Claims

1. A method for operating a storage stystem, the method comprising:

assigning volume block numbers (VBNs) to a volume,

assigning disk block numbers (DBNs) to each of a plurality of physical disks, the storage system including the physical disks;

mapping the VBNs to the DBNs of the plurality of physical disks, the mapping for a particular disk of the plurality of physicals disks stored in a disk label for the particlular disk; and

writing the disk label for the particular disk to the particular disk.

2. The method of claim 1 further comprising:

arranging the plurality of physical disks into a RAID subsystem.

3. The method of claim 2 further comprising:

organizing the RAID subsystem as one or more physical disks supporting a volume.

4. The method of claim 1 further comprising:

mapping a range of VBNs to a range of DBNs of the particular disk of the plurality of disks.

5. The method of claim 4 further comprising:

determining a noncontiguous VBN-to-DBN mapping.

6. The method of claim 1 further comprising:

mapping a base offset into a VBN range of the volume, a corresponding base offset into a DBN range of a related disk, and a size of DBN-to-VBN mapping.

7. The method of claim 1 further comprising:

exporting a raidmap from a RAID subsystem to a raidmap cache in a memory of the storage system.

8. A storage operating stystem apparatus comprising:

the storage operating system configured to assign volume block numbers (VBNs) to a volume;

a plurality of disks, each disk of the plurality of disks assigned disk block numbers (DBNs);

a raid map configured to map the VBNs to the DBNs of the plurality of physical disks, the mapping for a particular disk stored in a disk label for the particular disk; and

the disk label for the particular disk written to the particular disk.

9. The apparatus of claim 8 further comprising:

the RAID subsystem to maintain the raidmap.

10. The apparatus of claim 8 further comprising:

the RAID subsystem configured to organize one or more physical disks supporting the volume.

11. The apparatus of claim 8 further comprising:

a range of VBNs configured to map to a range of DBNs of the particular disk of the plurality of disks.

12. The apparatus of claim 11 further comprising:

input/output operations of the raidmap used to determine a noncontiguous VBN-to-DBN mapping within the RAID subsystem.

13. The apparatus of claim 8 further comprising:

the disk label to store a base offset into the VBN range of the volume, a base off-set into the DBN range corresponding to the VBN range, and a size of DBN-to-VBN mapping.

14. The apparatus of claim 13 further comprising:

the RAID subsystem to export a raidmap to a raidmap cache.

15. A method for operating a storage stystem in the event of a disk failure, the method comprising:

a volume having a volume block number (VBN) space;

creating a first raidmap to reconstruct a failed disk using a first portion of a replaced disk;

creating a second raidmap to map a second portion of the replaced disk into the VBN space; and

storing the first and second raidmaps in a disk label on the replaced disk.

16. The method of claim 15 further comprising:

replacing the failed disk with a larger disk.

17. The method of claim 16 further comprising:

mapping a capacity of the larger disk into a RAID subsystem of the storage system.

18. The method of claim 15 further comprising:

enabling separation of DBN ranges of the DBN space on the replaced disk from VBN ranges of the volume.

19. The method of claim 15 further comprising:

providing the RAID subsystem of the storage system, the RAID subsystem managing storage and retrieval of information, including the mapping parameters of the raidmap to and from the volume.

20. The method of claim 19 further comprising:

exporting the mapping parameters of the raidmap from the RAID subsystem to a write allocator of the storage system, the write allocator using the raidmap in performing input/output operations.

21. The method of claim 15 further comprising:

extending a VBN range of the VBN space by using the second portion of the replaced disk for an extended range of the VBN space.

22. The method of claim 21 further comprising:

mapping the extended range of the VBN space into a disk block number (DBN) space of the replaced disk.