Uninterrupted block-based restore operation using a read-ahead buffer

Patent metadata

Field	Value
Publication number	US-11940878-B2
Application number	US-202016789744-A
Country	US
Kind code	B2
Filing date	Feb 13, 2020
Priority date	Feb 13, 2020
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

Methods and systems for restoring data are described. According to some embodiments, the method, in response to receiving a first restore request, initiates a second restore request to a hybrid data buffer to route blocks of backup data to the hybrid data buffer. The method further invokes an interrupt service routine (ISR) that is initialized with reserved addresses. When the blocks of backup data are transmitted to the hybrid data buffer, the method further tags, by the ISR, the blocks of backup data to a specified location, where the specified location is one of the reserved addresses.

First claim

What is claimed is:

1. A computer-implemented method for restoring backup data in a data deduplication system, the method comprising:
initiating a restore request to a hybrid data buffer to route blocks of backup data to the hybrid data buffer;
invoking an interrupt service routine (ISR) that is initialized with reserved addresses in a construction container;
in response to determining that the blocks of backup data are transmitted to the hybrid data buffer, tagging, by the ISR, the blocks of backup data to a specified location, the specified location being one of the reserved addresses in the construction container;
in response to determining that an abort of a restore operation occurs, masking the ISR and freezing the hybrid data buffer;
during a next restore session, unmasking the ISR and checking the hybrid data buffer for the reserved addresses; and
in response to determining that there are empty addresses among the reserved addresses, routing blocks of backup data corresponding to the empty addresses to the construction container.

2. The method of claim 1 , wherein
the hybrid data buffer includes a read-ahead buffer and an operational buffer, and
the blocks of backup data are transmitted to the read-ahead buffer.

3. The method of claim 1 , further comprising:
monitoring states of the reserved addresses; and
routing the states of the reserved addresses to the ISR to track each of the blocks of backup data being read or retrieved from a target device.

4. The method of claim 1 , further comprising: in response to determining that the abort of the restore operation occurs, freezing states of the reserved addresses and terminating the restore operation.

5. The method of claim 1 , wherein the method is repeated until all of the blocks of backup data corresponding to the empty addresses are successfully read and routed onto the construction container.

6. The method of claim 2 , wherein the ISR holds a state of the read-ahead buffer.

7. A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor, cause the processor to perform operations, the operations comprising:
initiating a restore request to a hybrid data buffer to route blocks of backup data to the hybrid data buffer;
invoking an interrupt service routine (ISR) that is initialized with reserved addresses in a construction container;
in response to determining that the blocks of backup data are transmitted to the hybrid data buffer, tagging, by the ISR, the blocks of backup data to a specified location, the specified location being one of the reserved addresses in the construction container;
in response to determining that an abort of a restore operation occurs, masking the ISR and freezing the hybrid data buffer;
during a next restore session, unmasking the ISR and checking the hybrid data buffer for the reserved addresses; and
in response to determining that there are empty addresses among the reserved addresses, routing blocks of backup data corresponding to the empty addresses to the construction container.

8. The non-transitory machine-readable medium of claim 7 , wherein
the hybrid data buffer includes a read-ahead buffer and an operational buffer, and
the blocks of backup data are transmitted to the read-ahead buffer.

9. The non-transitory machine-readable medium of claim 7 , wherein the operations further comprise:
monitoring states of the reserved addresses; and
routing the states of the reserved addresses to the ISR to track each of the blocks of backup data being read or retrieved from a target device.

10. The non-transitory machine-readable medium of claim 7 , wherein the operations further comprise: in response to determining that the abort of the restore operation occurs, freezing states of the reserved addresses and terminating the restore operation.

11. The non-transitory machine-readable medium of claim 7 , wherein the operations are repeated until all of the blocks of backup data corresponding to the empty addresses are successfully read and routed onto the construction container.

12. The non-transitory machine-readable medium of claim 8 , wherein the ISR holds a state of the read-ahead buffer.

13. A data processing system, comprising:
a processor; and
a memory coupled to the processor to store instructions, which when executed by the processor, cause the processor to perform operations, the operations comprising:
initiating a restore request to a hybrid data buffer to route blocks of backup data to the hybrid data buffer;
invoking an interrupt service routine (ISR) that is initialized with reserved addresses in a construction container;
in response to determining that the blocks of backup data are transmitted to the hybrid data buffer, tagging, by the ISR, the blocks of backup data to a specified location, the specified location being one of the reserved addresses in the construction container;
in response to determining that an abort of a restore operation occurs, masking the ISR and freezing the hybrid data buffer;
during a next restore session, unmasking the ISR and checking the hybrid data buffer for the reserved addresses; and
in response to determining that there are empty addresses among the reserved addresses, routing blocks of backup data corresponding to the empty addresses to the construction container.

14. The data processing system of claim 13 , wherein
the hybrid data buffer includes a read-ahead buffer and an operational buffer, and
the blocks of backup data are transmitted to the read-ahead buffer.

15. The data processing system of claim 13 , wherein the operations further comprise:
monitoring states of the reserved addresses; and
routing the states of the reserved addresses to the ISR to track each of the blocks of backup data being read or retrieved from a target device.

16. The data processing system of claim 13 , wherein the operations further comprise: in response to determining that the abort of the restore operation occurs, freezing states of the reserved addresses and terminating the restore operation.

17. The data processing system of claim 13 , wherein the operations are repeated until all of the blocks of backup data corresponding to the empty addresses are successfully read and routed to the construction container.

18. The data processing system of claim 14 , wherein the ISR holds a state of the read-ahead buffer.

Assignees

• Emc Ip Holding Co Llc

Inventors

• Reddy A V Mahesh
• Battal Chetan
• Ambaljeri Mahantesh
• Shankar Dh Swaroop

Classifications

• G06F11/1448 Primary

  Management of the data involved in backup or backup restore · CPC title

• G06F16/183

  Provision of network file services by network file servers, e.g. by using NFS, CIFS (network file access protocols H04L67/1097) · CPC title

• G06F2201/80

  Database-specific techniques · CPC title

• G06F11/1464 Primary

  for networked environments · CPC title

• G06F16/174

  Redundancy elimination performed by the file system (error detection or correction of the data by redundancy in operations G06F11/14) · CPC title