Data storage access device

Abstract

A data storage access device for providing access by an external device to data stored according to a first file system on physical storage, comprises a file system interface operator ( 8 ) for providing a file system interface to the external device, wherein the file system interface represents data stored on the physical storage according to the first file system as being stored according to a second file system.

1 . A navigation device for providing access by an external device to data stored according to a first file system on physical storage, comprising:
 a file system interface operator for providing a file system interface to the external device, wherein the file system interface represents data stored on the physical storage according to the first file system as being stored according to a second file system, wherein the first file system is a power-safe file system.   
     
     
         2 . A device according to  claim 1 , further comprising:
 being configured to communicate with, a file system operator for accessing data on the physical storage according to the first file system.   
     
     
         3 . A device according to  claim 1 , wherein the first file system is of a first type and the second file system is of a second, different type. 
     
     
         4 . A device according to  claim 1 , wherein the file system interface operator is configured to intercept a request according to the second file system from the external device and to perform the request using the first file system. 
     
     
         5 . A device according to  claim 4 , wherein the file system interface operator is configured to respond to the request with a response in a response format of the second file system. 
     
     
         6 . A device according to  claim 4 , wherein the request comprises a request to perform an operation on at least one logical storage element of the second file system, for example a request to read or write at least one logical storage element of the second file system. 
     
     
         7 . A device according to  claim 6 , wherein the file system interface operator is configured to translate the request into a request according to the first file system. 
     
     
         8 . A device according to  claim 7 , wherein the file system interface operator is configured to translate the request into a request to perform an operation on at least one logical or physical storage element of the first file system, for example a request to read or write at least one logical storage element of the first file system. 
     
     
         9 . A device according to  claim 4 , wherein the file system interface operator is configured to respond to a read request by the external device by providing a response that comprises at least one logical storage element of the second file system. 
     
     
         10 . A device according to  claim 6 , wherein each logical storage element of the second file system comprises a block or a sector. 
     
     
         11 . A device according to  claim 1 , wherein the file system interface operator is configured to respond to a read request for the boot sector of the physical storage with a response that indicates that the physical storage is formatted according to a file system of the second type. 
     
     
         12 . A device according to  claim 1 , wherein the file system interface comprises representations of files, directories and/or sub-directories in the second file system that correspond to files, directories and/or sub-directories stored in the physical storage under the first file system. 
     
     
         13 . A device according to  claim 1 , wherein the file system interface operator is configured to update the file system interface in response to changes to files, directories or sub-directories stored in the physical storage under the first file system so that the file system interface represents the changes as occurring under the second file system. 
     
     
         14 . A device according to  claim 13 , wherein the file system interface operator represents the changes as occurring under the second file system by modifying metadata of the second file system. 
     
     
         15 . A device according to  claim 1 , wherein the file system interface is configured to represent at least some of the data stored on the physical storage under the first file system as being stored under the second file system, and to represent at least some of the data stored on the physical storage under the first file system as being stored under at least one further file system. 
     
     
         16 . A device according to  claim 1 , wherein the first file system comprises an Ext-type file system, and/or the second file system comprises a FAT-based file system or NTFS file system. 
     
     
         17 . A device according to  claim 1 , wherein the physical storage comprises NAND flash storage, and the first file system comprises a log-structured file system, for example JFFS2. 
     
     
         18 - 19 . (canceled)