Building stable storage area networks for compute clusters

• US 10,521,127 B2
• Filed: 09/13/2017
• Issued: 12/31/2019
• Est. Priority Date: 07/31/2017
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Jibbe, Mahmoud K., Lang, Dean, Parnell, Joey, Rodine, Ryan, Briner, Joshua
• Primary Examiner(s): Chappell, Daniel C.
• Application Number:
  US15/703,169
• Publication Number:
  US 20190034094A1
• Time in Patent Office: 839 Days
• CPC Class Codes: G06F 12/0808 with cache invalidating means G06F12/0815 takes precedence
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 12/0888 using selective caching, e.g. bypass
• CPC Class Codes: G06F 2212/1024 Latency reduction
• CPC Class Codes: G06F 2212/313 In storage device
• CPC Class Codes: G06F 2212/502 using adaptive policy
• CPC Class Codes: G06F 2212/621 Coherency control relating to peripheral accessing, e.g. from DMA or I/O device
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• 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 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Systems and methods that result in a stable storage system are provided. In the storage system, the latency spikes may be reduced when multiple volumes are aggregated into transfer sets according to system characteristics. The storage system transfers ownership of volumes in each transfer set as a single transaction. In the storage system, connectivity between the host and the storage controller is re-established based on the connectivity in a physical transport layer and a single path. In the storage system, pre-mature failback is also avoided when ownership of volumes is transferred back to a preferred storage controller when the same number of paths existed between the host and the preferred storage controller before and after a failover operation. Further, the storage system generates connectivity reports that display connectivity paths between hosts, storage controllers, and volumes.

Claims

1. A method comprising:

aggregating first volumes in a plurality of volumes into a first transfer set and second volumes in the plurality of volumes into a second transfer set according to system characteristics;

discontinuing I/O requests to volumes in the first transfer set and the second transfer set;

sequentially transferring ownership of the first volumes in the first transfer set to one or more storage controllers that have not owned the first volumes, and the second volumes in the second transfer set to one or more storage controllers that have not owned the second volumes, wherein the first volumes within the first transfer set are transferred as a first single transaction and the second volumes within the second transfer set are transferred as a second single transaction; and

reinstating the I/O requests to the first volumes in the first transfer set and the second volumes in the second transfer set.

2. The method of claim 1, wherein the system characteristics include ownership of at least one storage controller that owns a volume of the plurality of volumes.

3. The method of claim 1, wherein the system characteristics include media type of at least one storage device that is associated with a volume of the plurality of volumes.

4. The method of claim 1, wherein the system characteristics include Redundant Array of Independent/Inexpensive Disks (“

RAID”

) volume group membership.

5. The method of claim 1, wherein the system characteristics include workload type of applications that store data in the plurality of volumes.

6. The method of claim 1, further comprising:

changing a caching model for a cache that stores data associated with the first volumes in the first transfer set to a write through model.

7. The method of claim 1, further comprising:

flushing a cache that stores data associated with the first volumes in the first transfer set to underlying one or more storage devices.

8. The method of claim 1, wherein the aggregating occurs during a failback operation.

9. The method of claim 1, further comprising:

generating a connectivity report displaying the one or more storage controllers having ownership of the first volumes in the first transfer set.

10. A computing device comprising:

a non-transitory memory containing machine readable medium comprising machine executable code having stored thereon instructions for performing a method of transferring ownership of volumes; and

a processor coupled to the memory, the processor configured to execute the machine executable code to cause the processor to;

aggregate a first subset of volumes in a plurality of volumes into a first transfer set and a second subset of volumes in the plurality of volumes into a second transfer set;

change a caching model for at least one cache that stores data associated with the first subset of volumes and the second subset of volumes to a write-thru model;

flush the data in the at least one cache to underlying one or more storage devices;

discontinue I/O requests to the first subset of volumes and the second subset of volumes;

sequentially transfer ownership of the first subset of volumes in the first transfer set and the second subset of volumes in the second transfer set from a first storage controller to one or more other storage controllers that have not owned the first subset of volumes and the second subset of volumes, wherein the first subset of volumes are transferred as a first single transaction and the second subset set of volumes are transferred as a second single transaction; and

reinstate the I/O requests to the first subset of volumes and the second subset of volumes.

11. The computing device of claim 10, wherein the first subset of volumes and second subset of volumes are aggregated based on ownership of at least one storage controller that owns a volume in the plurality of volumes.

12. The computing device of claim 10, wherein the first subset of volumes and second subset of volumes are aggregated based on media type of at least one storage device that is associated with a volume in the plurality of volumes.

13. The computing device of claim 10, wherein the first subset of volumes and second subset of volumes are aggregated based on Redundant Array of Independent/Inexpensive Disks (“

RAID”

) volume group membership.

14. The computing device of claim 10, wherein the first subset of volumes and second subset of volumes are aggregated based on workload type of applications that store data in the plurality of volumes.

15. The computing device of claim 10, wherein the processor aggregates the plurality of volumes during a failback operation.

16. The computing device of claim 10, wherein the processor is further configured to execute the machine executable code to cause the processor to:

generate a connectivity report displaying the one or more storage controllers having ownership of volumes in the first transfer set.