Methods and systems for removing virtual machine snapshots

• US 9,665,440 B2
• Filed: 07/25/2016
• Issued: 05/30/2017
• Est. Priority Date: 08/29/2014
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Nimble Storage (Hewlett-Packard Enterprise Company)
• Inventors: Chelur, Raja Shekar, Wang, Juhsun, Ranganathan, Gaurav
• Primary Examiner(s): Bragdon, Reginald
• Assistant Examiner(s): WESTBROOK, MICHAEL L
• Application Number:
  US15/218,333
• Publication Number:
  US 20170017554A1
• Time in Patent Office: 309 Days
• Field of Search: None
• CPC Class Codes: G06F 11/1438 Restarting or rejuvenating
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/3409 for performance assessment
• CPC Class Codes: G06F 11/3485 for I/O devices
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 2009/45562 Creating, deleting, cloning virtual machine instances
• CPC Class Codes: G06F 2009/45575 Starting, stopping, suspending or resuming virtual machine instances
• CPC Class Codes: G06F 2201/815 Virtual middleware or OS functionality using virtual machines to implement generic software techniques for error detection or fault masking G06F11/1484
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• 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: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

Techniques are described herein which minimize the impact of virtual machine snapshots on the performance virtual machines and hypervisors. In the context of a volume snapshot which may involve (i) taking virtual machine snapshots of all virtual machines associated with the volume, (ii) taking the volume snapshot, and (iii) removing all the virtual machine snapshots, the virtual machine snapshots may be created in a first order and removed in a second order. Specifically, snapshots for busy virtual machines (i.e., virtual machines with higher disk write activity) may be created last and removed first. Consequently, snapshots of busy virtual machines are retained for shorter periods of time, thereby minimizing the effect of virtual machine snapshots on those virtual machines (and their associated hypervisors) that would be most negatively impacted by virtual machine snapshots.

Claims

1. A method for managing snapshots of a plurality of virtual machines instantiated on a host, each of the virtual machines storing data on a storage system communicatively coupled to the host, the virtual machine snapshots maintaining on the storage system a state of each of the virtual machines, the method comprising:

determining by the storage system an order of the virtual machines based on one or more metrics associated with the virtual machines, wherein the determined order orders the virtual machines by a decreasing disk write activity of the virtual machines; and

transmitting a first request from the storage system to a hypervisor manager, the first request requesting the virtual machine snapshots to be removed from the storage system in the determined order of the virtual machines.

2. The method of claim 1, further comprising:

in response to the transmitted first request, instructing by the hypervisor manager one or more hypervisors to remove, via a plurality of snapshot removal operations, the virtual machine snapshots from the storage system,

wherein the plurality of snapshot removal operations are initiated in the determined order of the virtual machines, and wherein the one or more hypervisors are instantiated on the host and are interfaced with the storage system via the hypervisor manager.

3. The method of claim 2, wherein the virtual machine snapshots are stored on a volume of the storage system, the method further comprising, prior to the removal of the virtual machine snapshots from the volume, taking by the storage system a volume snapshot of the volume.

4. The method of claim 3, further comprising, prior to taking the volume snapshot, transmitting a second request from the storage system to the hypervisor manager, the second request requesting the hypervisor manager to provide the one or more metrics associated with the virtual machines.

5. The method of claim 4, further comprising, prior to taking the volume snapshot, receiving from the hypervisor manager the one or more metrics associated with the virtual machines.

6. The method of claim 3, further comprising, after taking the volume snapshot, transmitting a third request from the storage system to the hypervisor manager, the third request requesting the hypervisor manager to provide the one or more metrics associated with the virtual machines.

7. The method of claim 6, further comprising, after taking the volume snapshot, receiving from the hypervisor manager the one or more metrics associated with the virtual machines.

8. A storage system communicatively coupled to a host on which a plurality of virtual machines are instantiated, the storage system comprising:

a main memory;

a storage array configured to store data belonging to each of the virtual machines, and configured to store a snapshot of each of the virtual machines, the virtual machine snapshots maintaining a state of each of the virtual machines;

a processor communicatively coupled to the main memory and the storage array; and

software instructions on the main memory that, when executed by the processor, cause the processor to;

determine an order of the virtual machines based on one or more metrics associated with the virtual machines, wherein the determined order orders the virtual machines by a decreasing disk write activity of the virtual machines; and

transmit a first request to a hypervisor manager, the first request requesting the virtual machine snapshots to be removed from the storage system in the determined order of the virtual machines.

9. The storage system of claim 8, further comprising a volume instantiated on the storage array, the volume configured to store the virtual machine snapshots.

10. The storage system of claim 9, further comprising software instructions on the main memory that, when executed by the processor, cause the processor to take a volume snapshot of the volume.

11. The storage system of claim 10, further comprising software instructions on the main memory that, when executed by the processor, cause the processor to transmit a second request to the hypervisor manager prior to taking the volume snapshot, the second request requesting the hypervisor manager to provide the one or more metrics associated with the virtual machines.

12. The storage system of claim 11, further comprising software instructions on the main memory that, when executed by the processor, cause the processor to receive from the hypervisor manager the one or more metrics associated with the virtual machines prior to taking the volume snapshot.

13. The storage system of claim 10, further comprising software instructions on the main memory that, when executed by the processor, cause the processor to transmit a third request to the hypervisor manager after taking the volume snapshot, the third request requesting the hypervisor manager to provide the one or more metrics associated with the virtual machines.

14. The storage system of claim 13, further comprising software instructions on the main memory that, when executed by the processor, cause the processor to receive from the hypervisor manager the one or more metrics associated with the virtual machines after taking the volume snapshot.

15. A non-transitory machine-readable storage medium for managing snapshots of a plurality of virtual machines instantiated on a host, each of the virtual machines storing data on a storage system communicatively coupled to the host, the virtual machine snapshots maintaining a state of each of the virtual machines on the storage system, the non-transitory machine-readable storage medium comprising software instructions that, when executed by a processor of the storage system, cause the processor to:

determine an order of the virtual machines based on one or more metrics associated with the virtual machines, wherein the determined order orders the virtual machines by a decreasing disk write activity of the virtual machines; and

transmit a first request to a hypervisor manager, the first request requesting the virtual machine snapshots to be removed from the storage system in the determined order of the virtual machines.

16. The non-transitory machine-readable storage medium of claim 15, further comprising software instructions that, when executed by the processor, cause the processor to take a volume snapshot of a volume of the storage system on which the virtual machine snapshots are stored.

17. The non-transitory machine-readable storage medium of claim 16, further comprising software instructions that, when executed by the processor, cause the processor to transmit a second request to the hypervisor manager prior to taking the volume snapshot, the second request requesting the hypervisor manager to provide the one or more metrics associated with the virtual machines.

18. The non-transitory machine-readable storage medium of claim 17, further comprising software instructions that, when executed by the processor, cause the processor to receive from the hypervisor manager the one or more metrics associated with the virtual machines prior to taking the volume snapshot.

19. The non-transitory machine-readable storage medium of claim 16, further comprising software instructions that, when executed by the processor, cause the processor to transmit a third request to the hypervisor manager after taking the volume snapshot, the third request requesting the hypervisor manager to provide the one or more metrics associated with the virtual machines.

20. The non-transitory machine-readable storage medium of claim 19, further comprising software instructions that, when executed by the processor, cause the processor to receive from the hypervisor manager the one or more metrics associated with the virtual machines after taking the volume snapshot.