Method and apparatus for locating data in computer systems

A multilevel caching system for locating data in a computer, said data being logically organized as files in a file system, said multilevel caching system comprising:

• a primary cache operating to provide storage for storing information relating to one or more files in the file system;
• a secondary cache operating to provide storage for storing information relating to another one or more files in the file system which is not provided in the primary cache;
• said secondary cache serving as a secondary cache which is searched after unsuccessful search of the primary cache in order to locate information relating to another one or more files in the file system;
• a file locator manager operating to first search the primary cache and then the secondary cache for information relating to a file in the file system and;
• wherein the file locator manager is configured to store information relating to one or more files in the secondary cache;
• said information being obtained during said searching of said storage device when it is determined that said information is neither available on the primary nor on the secondary cache, and
• wherein the information stored in said secondary cache includes information needed to locate at least another file that was encountered during said searching of said storage device when it is determined that said information is neither available on the primary nor on the secondary cache.

A method for locating data in a computer, said data being logically organized as one or more files in a file system, said method comprising:

• determining whether a filename associated with a file can be found in a primary cache;
• determining whether the filename can be found in a secondary cache when it is determined that the filename cannot be found in the primary cache;
• searching a storage device to locate at least a portion of data represented by the file on the storage device only when it is first determined that the filename associated with the file cannot be found in the secondary cache;
• storing in the secondary cache at least a portion of information obtained during said searching of said storage device when it is determined that the filename is neither in the primary cache, nor in the secondary cache;
• and
• wherein the information stored in the secondary cache includes at least one file reference, said file reference providing a reference which can be used to locate at least a portion of data represented by a file;
• and
• wherein the information stored in the secondary cache as a result of said searching of said storage device also includes at least another file reference, said another file reference providing a reference which can be used to locate at least another portion of data represented by another file which was encountered during said searching of said storage device.

A computer readable media including computer program code for locating data in a computer, said data being logically organized as one or more files in a file system, said computer readable media comprising:

• computer program code for determining whether a filename associated with a file can be found in a primary cache;
• computer program code for determining whether the filename can be found in a secondary cache when it is determined that the filename cannot be found in the primary cache;
• computer program code for searching a storage device to locate at least a portion of data represented by the file on the storage device when it is determined that the filename associated with the file is neither in the primary, nor in the secondary cache;
• and
• computer program code for storing in the secondary cache information obtained during said searching of said storage device when it is determined that the filename is neither in the primary, nor in the secondary cache
• wherein the information stored in said secondary cache includes information needed to locate at least another file that was encountered during said searching of said storage device when it is determined that said information is neither in the primary cache, nor in the secondary cache.