DYNAMIC MANAGEMENT OF EXPANDABLE CACHE STORAGE FOR MULTIPLE NETWORK SHARES CONFIGURED IN A FILE SERVER

• US 20180018270A1
• Filed: 05/22/2017
• Published: 01/18/2018
• Est. Priority Date: 07/12/2016
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: KILARU, Satish Chandra, KOTTOMTHARAYIL, Rajiv, KUMARASAMY, Paramasivam, KATCHER, William
• Granted Patent: US 10,437,937 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1446 Point-in-time backing up or restoration of persistent data
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1466 to make the backup process non-disruptive
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: G06F 2009/45579 I/O management, e.g. providing access to device drivers or storage
• CPC Class Codes: G06F 2211/1009 Cache, i.e. caches used in RAID system with parity
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• 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 9/45558 Hypervisor-specific management and integration aspects

Abstract

Expandable cache management dynamically manages cache storage for multiple network shares configured in a file server. Once a file is written to a directory or folder on a specially designated network share, such as one that is configured for “infinite backup,” an intermediary pre-backup copy of the file is created in an expandable cache in the file server that hosts the network share. On write operations, cache storage space can be dynamically expanded or freed up by pruning previously backed up data. This advantageously creates flexible storage caches in the file server for each network share, each cache managed independently of other like caches for other network shares on the same file server. On read operations, intermediary file storage in the expandable cache gives client computing devices speedy access to data targeted for backup, which is generally quicker than restoring files from backed up secondary copies.

Claims

1. A system for retrieving data from a network share cache if available instead of retrieving the data from a secondary copy, the system comprising:

a file server in communication with a first client computing device, wherein the file server comprises a plurality of storage volumes;

a secondary storage device in communication with the file server;

wherein the file server is configured to perform operations comprising;

receiving from a client computing device a read request in reference to a first file, wherein the read request designates a first network share configured in the file server as a source for the read request,

based on the designated first network share in the read request, directing the read request to a first cache manager that is associated with the first network share, wherein the first cache manager executes on the file server,

if the first cache manager determines that the read request can be served at least in part from a first set of storage volumes configured in the file server that are associated with the first network share, retrieving, by the first cache manager, at least some of the data requested by the read request from one or more first-network-share-specific folders configured in respective storage volumes in the first set, and

if the first cache manager determines that the read request cannot be served from the first set of storage volumes in the file server;

(i) triggering, by the first cache manager, a restore operation to restore the first file from a secondary copy stored on the secondary storage device, and

(ii) performing the restore operation by a restore interface module that executes on the file server in conjunction with a media agent that is associated with the secondary storage device, and

responding to the read request by the file server, based on at least one of;

(a) the restored first file and (b) the data retrieved from the first set of storage volumes in the file server.

2. The system of claim 1, the operations further comprising:

dividing, by a module that executes on the file server apart from the first cache manager, the restored first file into a plurality of portions including a first portion,

transmitting, by the module, each portion of the plurality of portions to the first cache manager, which is associated with the first network share, and

if a first storage volume of the first set of storage volumes that are associated with the first network share comprises sufficient storage space for the first portion of the restored first file, storing, by the first cache manager, the first portion of the restored first file to a respective first-network-share-specific folder in the first storage volume regardless of whether other portions of the restored first file are stored to the same first storage volume.

3. The system of claim 1, the operations further comprising:

if none of the first set of storage volumes that are associated with the first network share comprise sufficient storage space for a first portion of the restored first file, dynamically expanding the amount of storage available for the first network share on the file server by;

(i) identifying by the first cache manager a second storage volume configured in the file server, outside the first set, that comprises sufficient storage space for the first portion of the restored first file,

(ii) configuring by the first cache manager in the second storage volume a first-network-share-specific folder for storing data for the first network share and only for the first network share, thereby associating the second storage volume with the first network share, and further thereby adding the second volume to the first set of storage volumes that are associated with the first network share regardless of whether the second volume comprises data for another network share configured on the file server, and

(iii) storing by the cache manager the first portion of the restored first file to the first-network-share-specific folder configured in the second storage volume.

4. The system of claim 1, the operations further comprising:

if none of the first set of storage volumes that are associated with the first network share comprise sufficient storage space for a first portion of the restored first file,

(A) freeing up storage space for the first network share by pruning data, by the first cache manager, from one or more first-network-share-specific folders configured in the first set of storage volumes, wherein only data that has been previously backed up from the file server to at least one secondary copy can be pruned to free up storage space, and

(B) after the pruning, storing by the first cache manager the first portion of the restored first file to a first-network-share-specific folder in one of the first set of storage volumes that are associated with the first network share.

5. The system of claim 1 wherein the media agent also executes on the file server.

6. The system of claim 1 wherein the media agent executes on a secondary storage computing device that is in communication with the file server and with the secondary storage device.

7. A non-transitory computer-readable medium storing instructions that, when executed by at least one file server, cause the file server to perform operations comprising:

receiving from a client computing device a read request in reference to a first file, wherein the read request designates a first network share configured in the file server as a source for the read request;

based on the designated first network share in the read request, directing the read request to a first cache manager that executes on the file server and is associated with the first network share;

if the first cache manager determines that the read request can be served at least in part from a first set of storage volumes configured in the file server that are associated with the first network share,

retrieving, by the first cache manager, at least some of the data requested by the read request from one or more first-network-share-specific folders configured in respective storage volumes in the first set; and

if the first cache manager determines that the read request cannot be served from the first set of storage volumes in the file server;

(i) triggering by the first cache manager a restore operation to restore the first file from a secondary copy stored on a secondary storage device, and

(ii) performing the restore operation by a restore interface module that executes on the file server in conjunction with a media agent that is associated with the secondary storage device; and

responding to the read request by the file server, based on at least one of;

(a) the restored first file and (b) the data retrieved from the first set of storage volumes in the file server.

8. The non-transitory computer-readable medium of claim 7, the operations further comprising:

dividing, by a module that executes on the file server apart from the first cache manager, the restored first file into a plurality of portions including a first portion;

transmitting, by the module, each portion of the plurality of portions to the first cache manager associated with the first network share; and

if a first storage volume of the first set of storage volumes that are associated with the first network share comprises sufficient storage space for the first portion of the restored first file, storing, by the first cache manager, the first portion of the restored first file to a respective first-network-share-specific folder in the first storage volume regardless of whether other portions of the restored first file are stored to the same first storage volume.

9. The non-transitory computer-readable medium of claim 7, the operations further comprising:

if none of the first set of storage volumes that are associated with the first network share comprise sufficient storage space for a first portion of the restored first file, dynamically expanding the amount of storage available for the first network share on the file server by;

(i) identifying by the first cache manager a second storage volume configured in the file server, outside the first set, that comprises sufficient storage space for the first portion of the restored first file,

(ii) configuring by the first cache manager in the second storage volume a first-network-share-specific folder for storing data for the first network share and only for the first network share, thereby associating the second storage volume with the first network share, and further thereby adding the second volume to the first set of storage volumes that are associated with the first network share, regardless of whether the second volume comprises data for another network share configured on the file server, and

(iii) storing by the cache manager the first portion of the restored first file to the first-network-share-specific folder configured in the second storage volume.

10. The non-transitory computer-readable medium of claim 8, the operations further comprising:

if none of the first set of storage volumes that are associated with the first network share comprise sufficient storage space for a first portion of the restored first file,

(A) freeing up storage space for the first network share by pruning data, by the first cache manager, from one or more first-network-share-specific folders configured in the first set of storage volumes, wherein only data that has been previously backed up from the file server to at least one secondary copy can be pruned to free up storage space, and

(B) after the pruning, storing by the first cache manager the first portion of the restored first file to a first-network-share-specific folder in one of the first set of storage volumes that are associated with the first network share.

11. The non-transitory computer-readable medium of claim 7 wherein the media agent also executes on the file server.

12. The non-transitory computer-readable medium of claim 7 wherein the media agent executes on a secondary storage computing device that is in communication with the file server and with the secondary storage device.

13. A method for retrieving data from a network share cache if available instead of retrieving the data from a secondary copy, the method comprising:

receiving, by a file server from a client computing device, a read request in reference to a first file, wherein the read request designates a first network share configured in the file server as a source for the read request;

based on the designated first network share in the read request, directing the read request to a first cache manager that is associated with the first network share, wherein the first cache manager executes on the file server;

if the first cache manager determines that the read request can be served at least in part from a first set of storage volumes configured in the file server that are associated with the first network share, retrieving, by the first cache manager, at least some of the data requested by the read request from one or more first-network-share-specific folders configured in respective storage volumes in the first set;

if the first cache manager determines that the read request cannot be served from the first set of storage volumes in the file server;

(i) triggering by the first cache manager a restore operation to restore the first file from a secondary copy stored on a secondary storage device, and

(ii) performing the restore operation by a restore interface module that executes on the file server in conjunction with a media agent that is associated with the secondary storage device; and

responding to the read request by the file server, based on at least one of;

(a) the restored first file, and (b) the data retrieved from the first set of storage volumes in the file server.

14. The method of claim 13 further comprising:

dividing, by a module that executes on the file server apart from the first cache manager, the restored first file into a plurality of portions including a first portion;

transmitting, by the module, each portion of the plurality of portions to the first cache manager, which is associated with the first network share; and

if a first storage volume of the first set of storage volumes that are associated with the first network share comprises sufficient storage space for the first portion of the restored first file, storing by the first cache manager the first portion of the restored first file to a respective first-network-share-specific folder in the first storage volume regardless of whether other portions of the restored first file are stored to the same first storage volume.

15. The method of claim 13 further comprising:

if none of the first set of storage volumes that are associated with the first network share comprise sufficient storage space for the first portion of the restored first file, dynamically expanding the amount of storage available for the first network share on the file server by;

(i) identifying by the first cache manager a second storage volume configured in the file server, outside the first set, that comprises sufficient storage space for the first portion of the restored first file,

(ii) configuring by the first cache manager in the second storage volume a first-network-share-specific folder for storing data for the first network share and only for the first network share, thereby associating the second storage volume with the first network share, and further thereby adding the second volume to the first set of storage volumes that are associated with the first network share, regardless of whether the second volume comprises data for another network share configured on the file server, and

(iii) storing by the cache manager the first portion of the restored first file to the first-network-share-specific folder configured in the second storage volume.

16. The method of claim 13 further comprising:

if none of the first set of storage volumes that are associated with the first network share comprise sufficient storage space to store the first portion of the restored first file,

(A) freeing up storage space for the first network share by pruning data, by the first cache manager, from one or more first-network-share-specific folders configured in the first set of storage volumes, wherein only data that has been previously backed up from the file server to at least one secondary copy can be pruned to free up storage space, and

(B) after the pruning, storing by the first cache manager the first portion of the restored first file to a first-network-share-specific folder in one of the first set of storage volumes that are associated with the first network share.

17. The method of claim 13 wherein the media agent also executes on the file server.

18. The method of claim 13 wherein the media agent executes on a secondary storage computing device that is in communication with the file server and with the secondary storage device.

19. The method of claim 13 wherein the file server executes a plurality of cache managers that includes the first cache manager, wherein each cache manager is associated with a distinct network share identified on the file server.

20. The method of claim 13 wherein the file server executes a plurality of cache managers that includes the first cache manager, wherein each cache manager is associated with a distinct network share identified on the file server;

and

wherein each respective cache manager operates independently of the other cache managers, regardless of whether a given storage volume configured in the file server comprises data from more than one network share.