Virtual Disk Manipulation Operations

• US 20110197022A1
• Filed: 02/08/2010
• Published: 08/11/2011
• Est. Priority Date: 02/08/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Oshins, Jacob K., Neil, Michael L., Green, Dustin L.
• Granted Patent: US 8,627,000 B2
• Time in Patent Office: Days
• US Class Current: 711/112
• 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 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

Described is a technology by which a virtual hard disk is able to continue servicing virtual disk I/O (reads and writes) while a meta-operation (e.g., copying, moving, deleting, merging, compressing, defragmenting, cryptographic signing, lifting, dropping, converting, or compacting virtual disk data) is performed on the virtual disk. The servicing of virtual disk I/Os may be coordinated with meta-operation performance, such as by throttling and/or prioritizing the virtual disk I/Os. Also described is performing a meta-operation by manipulating one or more de-duplication data structures.

Claims

1. In a computing environment, a system comprising, a virtual disk comprising at least two overlapping layers, and a mechanism that handles I/O of a meta-operation that manipulates data of the virtual disk concurrent with servicing virtual disk read and write I/O of the virtual disk, including by preventing at least one meta-operation write to a virtual disk offset range concurrent with a virtual disk write to an overlapping virtual disk offset range.

2. The system of claim 1 wherein the meta-operation comprises copying, moving, deleting, merging, compressing, defragmenting, cryptographic signing, lifting, dropping, converting, or compacting virtual disk data.

3. The system of claim 1 wherein the mechanism allows concurrent meta operation writes and virtual disk writes to a virtual disk offset range when the virtual disk write cannot be damaged by the meta-operation write, or when at least two writes are from a same source and thus are writing the same data.

4. The system of claim 1 wherein the meta-operation manipulates less than all of the virtual disk data.

5. The system of claim 1 wherein the mechanism coordinates the servicing of virtual disk I/Os with meta-operation performance to allow the meta-operation to complete, to control virtual disk reads and writes versus meta-operation reads and writes, or to control interference of the meta-operation with other data traffic, or any combination of allowing the meta-operation to complete, controlling virtual disk reads and writes versus meta-operation reads and writes, or controlling interference of the meta-operation with other data traffic.

6. The system of claim 1 wherein the mechanism throttles or prioritizes, or both throttles and prioritizes, virtual disk virtual disk reads and writes to allow the meta-operation to complete.

7. The system of claim 1 wherein the mechanism throttles or prioritizes, or both throttles and prioritizes, meta-operation reads and writes to control interference with virtual disk reads and writes, or to control interference of the meta-operation with other data traffic, or to both control interference with virtual disk reads and writes and to control interference of the meta-operation with other data traffic.

8. The system of claim 1 wherein one or more communication channels used by the metadata operation are separable or changeable, or both separable and changeable, with respect to one or more communication channels used in servicing the virtual disk reads and writes.

9. The system of claim 1 wherein the meta-operation is performed at least in part by manipulating one or more de-duplication data structures.

10. The system of claim 9 wherein the meta-operation manipulates the one or more de-duplication data structures to compact the virtual disk, defragment the virtual disk, merge two or more layers of the virtual disk, convert the virtual disk to a different layout, lift the virtual disk, or drop the virtual disk.

11. The system of claim 9 wherein the meta-operation manipulates the one or more de-duplication data structures by at least one copy offload operation, at least one update operation, at least one delete operation, or at least one move offload operation, or any combination of at least one copy offload operation, at least one update operation, at least one delete operation, or at least one move offload operation.

12. The system of claim 9 wherein the meta-operation copies or moves, or both copies and moves, both payload data and metadata.

13. In a computing environment, a method performed on at least one processor, comprising, receiving a meta-operation write at a virtual disk having at least two layers, and determining whether the meta-operation write is concurrent with any other write to overlapping layers at a same virtual disk offset range, and if not, allowing the write to proceed.

14. The method of claim 13 further comprising, determining whether there is an exception that allows the meta-operation write, including determining that the virtual disk write cannot be damaged by the write, or determining that the write and the other write are from a same source, and if so, allowing the write, and if not, preventing the write.

15. The method of claim 13 further comprising, throttling the write and other I/O of the meta-operation, or prioritizing the write and other I/O of the meta-operation, or both throttling and prioritizing the write and other I/O of the meta-operation to control interference with virtual disk reads and writes, or to control interference of the meta-operation with other data traffic, or to both control interference with virtual disk reads and writes and to control interference of the meta-operation with other data traffic.

16. The method of claim 13 further comprising, throttling the servicing of virtual disk writes to allow a meta-operation that corresponds to the meta-operation write to complete.

17. The method of claim 13 further comprising, changing a set of one or more files or devices used to store virtual disk data to a new set, including holding I/Os that use the set of one or more files or devices, waiting for in-flight I/Os using the set of one or more files or devices to complete, changing to use the new set of one or more files or devices, and stopping holding of the I/Os to be processed with respect to the new set.

18. One or more computer-readable media having computer-executable instructions, which when executed perform steps, comprising:

receiving I/O corresponding to a meta-operation on a virtual disk; and

determining whether the I/O can be handled by manipulating one or more de-duplication data structures, and if so, manipulating the one or more de-duplication data structures to perform at least part of the meta-operation.

19. The one or more computer-readable media of claim 18 wherein the meta-operation manipulates the one or more de-duplication data structures to compact the virtual disk, defragment the virtual disk, merge two or more layers of the virtual disk, convert the virtual disk to a different layout, lift the virtual disk, or drop the virtual disk.

20. The one or more computer-readable media of claim 18 wherein manipulating the one or more de-duplication data structures comprises performing at least one copy offload operation, at least one update operation, at least one delete operation, or at least one move offload operation, or any combination of performing at least one copy offload operation, at least one update operation, at least one delete operation, or at least one move offload operation.