System, Method and Computer Program Product for Recovering Stub Files

Abstract

A read cache may include portions of files stored on media of a media library. Embodiments described herein may include systems and methods for restoring a read cache, including restoring stub files to a read cache on an ad hoc basis.

What is claimed is: 
     
         1 . A system for recovering a read cache comprising:
 a media library, comprising:
 a set of drives, and 
 a set of media; and 
   an archive node appliance coupled to the media library and a set of hosts, the archive node appliance comprising a processor, a data store and a computer readable medium storing a set of computer executable instructions executable on the processor to:
 maintain a read cache comprising portions of files stored on the set of media; 
 receive a request from a network file system interface client for a first file at a first location; 
 locate the first file at a second location on a media of the media library, wherein the second location mirrors the first location; 
 read the first file from the media of the media library; and 
 populate the read cache with a stub file for the first file using file data read from the media. 
   
     
     
         2 . The system for recovering a read cache of  claim 1 , wherein the set of computer executable instructions are further executable to restore a set of configuration data from a backup set of configuration data. 
     
     
         3 . The system for recovering a read cache of  claim 2 , wherein the configuration data comprises a mapping between the first location and a third location in a data store. 
     
     
         4 . The system of recovering a read cache of  claim 3 , wherein the set of computer executable instructions are further executable to populate the stub file at the third location. 
     
     
         5 . The system for recovering a read cache of  claim 1 , wherein the set of computer executable instructions are further executable to respond to one or more subsequent read requests for data of the first file using file data read from the media. 
     
     
         6 . The system for recovering a read cache of  claim 1 , wherein the set of computer executable instructions are further executable to respond to one or more subsequent read requests for data of the first file using file data from the data store. 
     
     
         7 . The system for recovering a read cache of  claim 1 , wherein the media library is a tape library and the set of media comprise a set of tapes formatted according to a Linear Tape File System. 
     
     
         8 . A computer program product comprising a non-transitory computer readable medium storing a set of computer executable instructions comprising instructions for:
 maintaining a read cache of portions of files stored on media of a media library;   receiving a request from a network file system interface client for a first file at a first location;   locating the first file at a second location on a media of the media library, wherein the second location mirrors the first location;   reading the first file from the media of the media library; and   populating the read cache with a stub file for the first file using file data read from the media.   
     
     
         9 . The computer program product of  claim 8 , wherein the set of computer executable instructions further comprise instructions for restoring a set of configuration data from a backup set of configuration data. 
     
     
         10 . The computer program product of  claim 9 , wherein the configuration data comprises a mapping between the first location and a third location in a data store. 
     
     
         11 . The computer program product of  claim 10 , wherein the set of computer executable instructions further comprise instructions to populate the stub file at the third location. 
     
     
         12 . The computer program product of  claim 8 , wherein the set of computer executable instructions further comprise instructions for responding to one or more subsequent read requests for data of the first file using file data read from the media. 
     
     
         13 . The computer program product of  claim 8 , wherein the set of computer executable instructions further comprise instructions for responding to one or more subsequent read requests for data of the first file using file data from a data store. 
     
     
         14 . The computer program product of  claim 8 , wherein the media library is a tape library and the media comprise a set of tapes formatted according to a Linear Tape File System. 
     
     
         15 . A method for recovering a read cache comprising:
 maintaining a read cache comprising portions of files stored on media of a media library;   receiving a request from a network file system interface client for a first file at a first location;   locating the first file at a second location on a media of the media library, wherein the second location mirrors the first location;   reading the first file from the media of the media library; and   populating the read cache with a stub file for the first file from file data read from the media.   
     
     
         16 . The method of  claim 15 , further comprising restoring a set of configuration data from a backup set of configuration data. 
     
     
         17 . The method of  claim 16 , wherein the configuration data comprises a mapping between the first location and a third location in a data store. 
     
     
         18 . The method of  claim 17 , further comprising populating the stub file at the third location. 
     
     
         19 . The method of  claim 15 , further comprising responding to one or more subsequent read requests for data of the first file using file data read from the media. 
     
     
         20 . The method of  claim 15 , further comprising responding to one or more subsequent read requests for data of the first file using file data from a data store. 
     
     
         21 . The method of  claim 15 , wherein the media library is a tape library and the media comprise a set of tapes formatted according to a Linear Tape File System.