Resynchronization of objects in a virtual storage system

Patent metadata

Field	Value
Publication number	US-2025028471-A1
Application number	US-202318356125-A
Country	US
Kind code	A1
Filing date	Jul 20, 2023
Priority date	Jul 20, 2023
Publication date	Jan 23, 2025
Grant date	—

Abstract

An example method of resynchronizing a first replica of an object and a second replica of an object in an object storage system, includes: determining, by storage software in response to the second replica transitioning from failed to available, a stale sequence number for the second replica, the storage software having associated the stale sequence number with the second replica when the second replica failed; querying, by the storage software, block-level metadata for the object using the stale sequence number, the block-level metadata relating logical blocks of the object with sequence numbers for operations on the object; determining, by the software as a result of the querying, a set of the logical blocks each related to a sequence number being the same or after the stale sequence number; and copying, by the storage software, data of the set of logical blocks from the first replica to the second replica.

First claim

What is claimed is:

1 . A method of resynchronizing a first replica of an object and a second replica of an object in an object storage system, the object storge system providing storage for a host executing storage software, the method comprising:
determining, by the storage software in response to the second replica transitioning from failed to available, a stale sequence number for the second replica, the storage software having associated the stale sequence number with the second replica when the second replica failed; querying, by the storage software, block-level metadata for the object using the stale sequence number, the block-level metadata relating logical blocks of the object with sequence numbers for operations on the object; determining, by the software as a result of the querying, a set of the logical blocks each related to a sequence number being the same or after the stale sequence number; and copying, by the storage software, data of the set of logical blocks from the first replica to the second replica.

2 . The method of claim 1 , further comprising:
activating, by the storage software, the second replica after the copying.

3 . The method of claim 1 , wherein the storage software determines extents representing the set of logical blocks from the querying, each of the extents indicating a starting logical block and an offset from the starting logical block, and wherein the storage software copies the data using the extents.

4 . The method of claim 1 , wherein the sequence numbers are unique and the storage software changes the sequence number for each of the operations.

5 . The method of claim 4 , wherein the stale sequence number is one of the sequence numbers.

6 . The method of claim 1 , wherein the host is part of a cluster of hosts, the hosts including local storage devices aggregated to form the object storage system.

7 . The method of claim 6 , wherein the block-level metadata further relates the logical blocks with physical blocks of the local storage devices.

8 . A non-transitory computer readable medium comprising instructions to be executed in a computing device to cause the computing device to carry out a method of resynchronizing a first replica of an object and a second replica of an object in an object storage system, the object storge system providing storage for a host executing storage software, the method comprising:
determining, by the storage software in response to the second replica transitioning from failed to available, a stale sequence number for the second replica, the storage software having associated the stale sequence number with the second replica when the second replica failed; querying, by the storage software, block-level metadata for the object using the stale sequence number, the block-level metadata relating logical blocks of the object with sequence numbers for operations on the object; determining, by the software as a result of the querying, a set of the logical blocks each related to a sequence number being the same or after the stale sequence number; and copying, by the storage software, data of the set of logical blocks from the first replica to the second replica.

9 . The non-transitory computer readable medium of claim 8 , further comprising:
activating, by the storage software, the second replica after the copying.

10 . The non-transitory computer readable medium of claim 8 , wherein the storage software determines extents representing the set of logical blocks from the querying, each of the extents indicating a starting logical block and an offset from the starting logical block, and wherein the storage software copies the data using the extents.

11 . The non-transitory computer readable medium of claim 8 , wherein the sequence numbers are unique and the storage software changes the sequence number for each of the operations.

12 . The non-transitory computer readable medium of claim 11 , wherein the stale sequence number is one of the sequence numbers.

13 . The non-transitory computer readable medium of claim 8 , wherein the host is part of a cluster of hosts, the hosts including local storage devices aggregated to form the object storage system.

14 . The non-transitory computer readable medium of claim 13 , wherein the block-level metadata further relates the logical blocks with physical blocks of the local storage devices.

15 . A computer system, comprising:
a hardware platform comprising an interface to an object storage system, the object storage system storing an object having a first replica and a second replica; system software, executing on the hardware platform, including storage software configured to:
determine, in response to the second replica transitioning from failed to available, a stale sequence number for the second replica, the storage software having associated the stale sequence number with the second replica when the second replica failed;
query block-level metadata for the object using the stale sequence number, the block-level metadata relating logical blocks of the object with sequence numbers for operations on the object;
determine, as a result of the querying, a set of the logical blocks each related to a sequence number being the same or after the stale sequence number; and
copy data of the set of logical blocks from the first replica to the second replica.

16 . The computer system of claim 15 , wherein the storage software is configured to:
activate the second replica after the copying.

17 . The computer system of claim 15 , wherein the storage software determines extents representing the set of logical blocks from the querying, each of the extents indicating a starting logical block and an offset from the starting logical block, and wherein the storage software copies the data using the extents.

18 . The computer system of claim 15 , wherein the sequence numbers are unique and the storage software changes the sequence number for each of the operations.

19 . The computer system of claim 18 , wherein the stale sequence number is one of the sequence numbers.

20 . The computer system of claim 15 , wherein the host is part of a cluster of hosts, the hosts including local storage devices aggregated to form the object storage system.

Assignees

• Vmware Inc

Inventors

• Ramanan Venkata
• Knauft Eric
• Renauld Pascal
• Rangaswamy Sandeep
• Thokala Sudheer

Classifications

• G06F11/2094

  Redundant storage or storage space (G06F11/2056 takes precedence) · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/065 Primary

  Replication mechanisms · CPC title

• G06F3/0619 Primary

  in relation to data integrity, e.g. data losses, bit errors · CPC title