Systems and methods for managing data input/output operations in a virtual computing environment

• US 10,365,938 B2
• Filed: 11/05/2015
• Issued: 07/30/2019
• Est. Priority Date: 05/23/2011
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Joshi, Vikram, Luan, Yang, Apte, Manish R., Vidwans, Hrishikesh A., Brown, Michael F.
• Primary Examiner(s): Bragdon, Reginald G
• Assistant Examiner(s): Namazi, Mehdi
• Application Number:
  US14/933,806
• Publication Number:
  US 20160062787A1
• Time in Patent Office: 1,363 Days
• CPC Class Codes: G06F 12/084 with a shared cache
• CPC Class Codes: G06F 12/0871 Allocation or management of cache space
• CPC Class Codes: G06F 2009/45579 I/O management, e.g. providing access to device drivers or storage
• CPC Class Codes: G06F 2009/45583 Memory management, e.g. access or allocation
• CPC Class Codes: G06F 2212/152 Virtualized environment, e.g. logically partitioned system
• CPC Class Codes: G06F 2212/601 Reconfiguration of cache memory
• CPC Class Codes: G06F 2212/6042 Allocation of cache space to multiple users or processors
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

Systems and methods for managing data input/output operations are described that include virtual machines operating with a shared storage within a host. In such a system, a computer-implemented method is provided for dynamically provisioning cache storage while operating system applications continue to operate, including stalling the virtual machine'"'"'s local cache storage operations, changing the provision of cache storage size; and resuming the operations of the virtual machine.

Claims

1. A computer-implemented method of dynamically provisioning cache storage while one or more operating system applications continue to operate, comprising:

stalling local cache storage operations on a cache storage for a first virtual machine of a host;

while the local cache storage operations are stalled;

continuing to perform input/output (I/O) operations, by the first virtual machine, on a shared storage device without utilizing the cache storage; and

increasing a storage size of a first amount of storage space in the cache storage allocated to the first virtual machine; and

in response to completing the increase in storage size, resuming the local cache storage operations of the virtual machine on the cache storage.

2. The computer-implemented method according to claim 1, wherein stalling the local cache storage operations includes stopping the sending of I/O data transfers from the first virtual machine to the cache storage.

3. The computer-implemented method according to claim 1, wherein stalling the local cache storage operations further includes allowing outstanding I/O data transfers between the first virtual machine and the cache storage to complete.

4. The computer-implemented method according to claim 1, wherein the one or more operating system applications on the first virtual machine continue to operate while the local cache storage operations are stalled.

5. The computer-implemented method according to claim 1, wherein I/O data transfers for the first virtual machine are sent to a primary storage on the host while the local cache storage operations are stalled.

6. The computer-implemented method according to claim 1, further comprising decreasing a second amount of storage space allocated to a second virtual machine within the host in response to increasing the first amount of storage space allocated to the first virtual machine.

7. The computer-implemented method according to claim 1, wherein storage space in the cache storage is allocated for use by a plurality of virtual machines located within the host.

8. The computer-implemented method according to claim 1, wherein the local cache storage operations are stalled in response to determining that the first amount of storage space allocated to the first virtual machine prior to the stall is insufficient in size for the first virtual machine.

9. A virtualized computing system comprising:

a plurality of virtual machines, wherein each virtual machine includes an input/output driver for intercepting input/output operations associated with its virtual machine;

a shared data cache; and

a cache provisioner communicating with the plurality of virtual machines and the shared data cache, the cache provisioner configured to;

allocate portions of the shared data cache to each virtual machine based on the cache storage capacity needed by individual virtual machines,

stall local cache storage operations on a portion of the shared data cache while modifying a size of the portion of the shared data cache allocated to a virtual machine, and

while the local cache storage operations are stalled, continue to perform input/output operations, by the virtual machine, on a shared storage device without utilizing the shared cache storage.

10. The virtualized computing system of claim 9, wherein each of the plurality of virtual machines further includes a cache management system configured to determine capacities required by each respective virtual machine.

11. The virtualized computing system of claim 9, wherein the cache provisioner is configured to balance allocations among the plurality of virtual machines.

12. A computer-implemented method of transferring a virtual machine operating a virtual main storage drive within a first local storage of a cache allocated to a first host from the first host to a second host that shares the cache with the first host while one or more operating system applications continue to operate on the virtual machine, comprising:

stalling storage operations on the first local storage for the virtual machine;

continuing to perform input/output (I/O) operations, by the first virtual machine, on a shared storage device without utilizing the first local storage while the storage operations are stalled;

transferring the storage operations for the virtual machine to the second host while the storage operations are stalled;

provisioning the virtual machine with a second local storage in the cache allocated to the second host; and

resuming the operations of the virtual machine in the second host using the second local storage in response to the virtual machine being provisioned with the second local storage.

13. The computer-implemented method according to claim 12, wherein stalling the storage operations is performed by a hypervisor, stopping the sending of I/O data transfers from the virtual machine to the first local storage.

14. The computer-implemented method according to claim 12, wherein stalling the storage operations further includes allowing outstanding I/O data transfers between the virtual machine and the first local storage to complete.

15. The computer-implemented method according to claim 12, further comprising:

in response to a stall, transmitting I/O data transfers to a primary storage until the storage operations for the virtual machine are resumed in the second host.

16. The computer-implemented method according to claim 12, wherein provisioning the virtual machine with the second local storage allocated to the second host includes purging the virtual machine of all data transfer information associated with the first host before resuming operations in the second host.

17. An apparatus comprising:

means for stalling storage operations of a virtual machine on a local cache of cache storage allocated to the virtual machine;

means for continuing to perform input/output operations, by the virtual machine, on a shared storage device without utilizing the cache storage, while the local cache storage operations are stalled;

means for changing a provision of the cache to increase a storage space size of the local cache-while the local cache storage operations are stalled; and

means for resuming the storage operations of the virtual machine with limited read capability in the provisioned cache storage space.

18. The apparatus according to claim 17, wherein the means for resuming the storage operations of the virtual machine with limited read capability includes means for allowing the virtual machine to read from only the local cache that the virtual machine has previously written to.

19. A virtualized computing system comprising:

a plurality of virtual machines, wherein each virtual machine includes;

an input/output driver for intercepting input/output operations associated with its virtual machine, and

a virtual disk representing a virtual main drive storage;

a shared data cache for access by the plurality of virtual machines that have portions of the cache allocated to individual virtual machines for main drive storage that may change in size; and

a shared storage device for the plurality of virtual machines,

wherein;

a virtual machine is configured to;

stall local cache storage operations on the shared data cache during a process of reallocating a portion size to the virtual machine, and

continue to perform input/output operations on the shared storage device without utilizing the cache storage while the local cache storage operations are stalled.

20. The virtualized computing system according to claim 19, further comprising a cache provisioner communicating with the plurality of virtual machines and the shared data cache, the cache provisioner configured to dynamically allocate portions of the shared data cache to each virtual machine based on the cache storage capacity needed by individual virtual machines.