Synthesizing a restore image from one or more secondary copies to facilitate data restore operations to a file server

Patent metadata

Field	Value
Publication number	US-11921591-B2
Application number	US-202217673154-A
Country	US
Kind code	B2
Filing date	Feb 16, 2022
Priority date	Dec 7, 2017
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

An illustrative media agent (MA) in a data storage management system instructs a NAS file server (filer) to restore an MA-created synthesized-copy instead of larger filer-created backup copies. The synthesized-copy is designed only for the particular files to be restored and mimics, and is typically much smaller than, a filer-created backup copy. The synthesized-copy is fed to the filer on restore as a “restore data image.” When receiving a restore request for certain backed-up data files, the MA synthesizes the synthesized-copy on the fly. The MA generates a header mimicking a filer-created backup header; extracts files from filer-created backup copies arranging them within the synthesized-copy as if in filer-created backups; and instructs filer to perform a full-volume restore from the synthesized-copy. The MA serves the synthesized-copy piecemeal as available, rather than waiting to synthesize the entire synthesized-copy. The synthesized-copy is not stored at the MA.

First claim

What is claimed is:

1. A system comprising:
a computing device comprising one or more processors and computer memory, wherein the computing device is in communication with a file server, and wherein the computing device is configured to:
receive a request to restore, to the file server, one or more first data files that are backed up in one or more backup copies, wherein the one or more backup copies were previously generated by the file server, in an arrangement defined by the file server, and wherein the one or more first data files are fewer than a plurality of data files that are backed up in the one or more backup copies;
instruct the file server to perform a full-volume restore operation to the file server, wherein the file server is instructed to use, as a source location to restore from in the full-volume restore operation, a volume-identifier that is configured at the computing device;
initiate generating of a restore-image, wherein the restore-image comprises the one or more first data files indicated in the request and excludes other data files among the plurality of data files, wherein to generate the restore-image the computing device is further configured to:
(i) configure a first header for the restore-image, wherein the first header is readable by the file server as a header for a backup copy generated by the file server,
(ii) from the one or more backup copies, retrieve respective file data and a respective file header for each of the one or more first data files, and
(iii) within the restore-image, arrange the respective file data and the respective file header that were retrieved for each of the one or more first data files, into a sequence that is compatible with the file server performing the full-volume restore operation; and
in response to one or more read requests addressed to the volume-identifier, which are received from the file server performing the full-volume restore operation, transmit data blocks of the restore-image to the file server, without waiting to generate the restore-image in its entirety at the computing device, until all data blocks of the restore-image have been transmitted to the file server for the full-volume restore operation.

2. The system of claim 1 , wherein the first header is based at least in part on information collected by the computing device from the one or more backup copies, which were generated by the file server and which were stored by the computing device at secondary storage.

3. The system of claim 1 , wherein the computing device is further configured to: generate the restore-image dynamically, in response to the request to restore to the file server the one or more first data files.

4. The system of claim 1 , wherein to generate the restore-image, the computing device is further configured to: renumber original inode identifiers of the one or more first data files to fit into the sequence within the restore-image, wherein the sequence enables the file server to restore the one or more first data files of the restore-image via the full-volume restore operation even though at least some of the one or more first data files are non-contiguous within the one or more backup copies.

5. The system of claim 1 , wherein the restore-image is transmitted by the computing device to the file server, block-by-block, without waiting to generate the restore-image in its entirety at the computing device.

6. The system of claim 1 , wherein the computing device is further configured to:
prior to receiving the request to restore the one or more first data files, instruct the file server to back up data stored on the file server into a plurality of backup copies, which includes the one or more backup copies;
cause the plurality of backup copies to be stored, as received from the file server, at secondary storage, wherein the secondary storage comprises one or more data storage devices;
store at a data structure on the computing device, information about data files in the plurality of backup copies; and
wherein the first header generated for the restore-image is based on the information in the data structure.

7. The system of claim 1 , wherein the first header is based at least in part on information collected by the computing device from the one or more backup copies generated by and received from the file server.

8. The system of claim 1 , wherein the computing device is further configured to: transmit the data blocks of the restore-image to the file server, as the data blocks of the restore-image become available at the computing device and without generating the restore-image in its entirety at the computing device.

9. The system of claim 1 , wherein to arrange the respective file data and the respective file header into the sequence within the restore-image, the computing device is further configured to: renumber one or more original inode identifiers of the one or more first data files retrieved from the one or more backup copies to fit into the sequence within the restore-image.

10. The system of claim 1 , wherein the computing device is configured to enable the file server to restore the one or more first data files from the restore-image instead of the file server restoring all of the one or more backup copies.

11. The system of claim 1 , wherein the full-volume restore operation causes the one or more first data files, as arranged in the restore-image, to be restored to the file server, without restoring the other data files among the plurality of data files that are backed up in the one or more backup copies.

Assignees

• Commvault Systems Inc

Inventors

• Karthikeyan Sowdambiga
• Littlefield Duncan Alden

Classifications

• G06F11/1464 Primary

  for networked environments · CPC title

• G06F3/0619

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

• G06F3/064

  Management of blocks · CPC title

• G06F3/065

  Replication mechanisms · CPC title

• G06F3/067

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