MANAGING VIRTUAL HARD DRIVES AS BLOBS

• US 20110119668A1
• Filed: 11/16/2009
• Published: 05/19/2011
• Est. Priority Date: 11/16/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: WANG, JU, ZUO, YUE, EDWARDS, ANDREW JAMES, ARAFEH, SAMER, ENGINEER, ANU, CALDER, BRADLEY GENE
• Granted Patent: US 8,516,137 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• CPC Class Codes: G06F 15/161 Computing infrastructure, e.g. computer clusters, blade chassis or hardware partitioning casings, cabinets, racks or drawers for data centers H05K5/00
• CPC Class Codes: G06F 3/06 Digital input from, or digital output to, record carriers , e.g. RAID, emulated record carriers or networked record carriers
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• 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]
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox

Abstract

Cloud computing platforms having computer-readable media that perform methods to manage virtual hard drives as blobs are provided. The cloud computing platform includes fabric computers and blob stores. The fabric computers execute virtual machines that implement one or more applications that access virtual hard drives. The data in the virtual hard drives is accessed, via a blob interface, from blobs in the blob stores. The blob stores interface with a driver that translates some application input/output (I/O) requests destined to the virtual hard drives to blob commands when accessing data in the virtual hard drives.

Claims

1-20. -20. (canceled)

21. A computer-implemented method to manage virtual hard drives as blobs in a cloud computing platform, the method comprising:

creating a blob in a blob store that is exposed as a virtual hard drive to one or more applications;

mounting the virtual hard drive;

and

managing read and write requests to the virtual hard drive.

22. The computer-implemented method of claim 21, wherein the one or more applications are executed on a virtual machine and the read and write requests are managed by a driver in the cloud computing platform.

23. The computer-implemented method of claim 21, further comprising:

formatting the virtual hard drive as one of an N-T-F-S file system or an F-A-T file system.

24. The computer-implemented method of claim 21, wherein a driver intercepts all I/O requests to the virtual hard drive and reroutes the I/O requests to the blob in the blob store.

25. The computer-implemented method of claim 24, wherein blobs are accessed and manipulated via a blob interface available to the driver.

26. The computer-implemented method of claim 24, wherein blobs are uploaded, downloaded, or debugged via a blob interface available to some applications.

27. The computer-implemented method of claim 24, wherein a snapshot of the blob is created via the blob interface to allow additional applications to concurrently read data stored in the blob.

28. The computer-implemented method of claim 24, wherein application writes in the I/O requests are committed to the blob store before acknowledging success back to the application.

29. The computer-implemented method of claim 28, wherein exclusive write access is provided to the blob for an application via a blob lease that expires after a specified time period.

30. The computer-implemented method of claim 29, wherein the application conditionally writes to the blob based on the validity of the lease while other applications are allowed to read from the blob.

31. One or more computer readable media storing instructions to perform a method to manage virtual hard drives as blobs in a cloud computing platform, the method comprising:

receiving I/O requests for a virtual hard drive from an application executing on a virtual machine in the cloud computing platform; and

managing, by a driver, I/O requests to the virtual hard drive, wherein the driver orders overlapping I/O requests to the blob in the blob store, and transmits nonoverlapping I/O requests in parallel to the blobs in the blob store.

32. The computer-readable media of claim 31, wherein a sequence number is associated with the I/O request to prevent overwriting prior writes with older stale writes to the same data that is still in the cloud computing platform.

33. The computer-readable media of claim 32, wherein the driver increases the sequence numbers to ignore a prior write that was not acknowledged by the blob store.

34. The computer-readable media of claim 31, further comprising updating a local cache on the virtual machine with a write request, wherein the update to the local cache occurs either after an acknowledgement is received from the blob store, or in parallel with a write to the blob store but the update is available after the acknowledgement is received from the blob store.

35. The computer-readable media of claim 34, wherein all or part of the local cache is flushed after an application or virtual machine failure when the cache and blob are inconsistent.

36. A cloud computing platform that manages virtual hard drives as blobs, the cloud computing platform comprising:

fabric computers configured to execute virtual machines that implement applications, which access virtual hard drives to read and write data; and

blob stores configured to store blobs that are exposed as virtual hard drives to the applications, wherein different application programming interfaces and semantics enable access to the blobs and virtual hard drives.

37. The cloud computing platform of claim 36, wherein the fabric computers comprise a local cache that caches blob data, a blob library storing blob commands, and a driver that translates virtual hard drive I/O instructions to blob commands.

38. The cloud computing platform of claim 37, wherein the local cache stores a cyclic redundancy check code for each data block to determine whether an error exists in the data block before using the data block.

39. The cloud computing platform of claim 38, wherein the local cache and the blob are synchronized to allow the application to complete requests using the data stored in the local cache.

40. The cloud computing platform of claim 36, wherein the blobs are leased for a specific period of time by the applications, and the applications continuously renew the leases to maintain access the virtual hard drives corresponding to the blobs.