Patent ID: 9088591
Filing Date: 2015-07-21
Classification: G06F,H04L

Abstract:
1. A method for obtaining access to an attributes record for a file stored in a file system, wherein the attributes record is stored in one of a plurality of data storage units that store data for the file system and comprises a plurality of references to data blocks of the data storage units that include data for the file, said method comprising: maintaining, in each of the data storage units, a lookup table that is persistently stored in the data storage unit, wherein each entry in the lookup table comprises a reference to an attributes record stored in the data storage unit and a pathname in the file system related to a file or directory corresponding to the attributes record; receiving a request to access a first file in the file system, wherein the request comprises a first pathname corresponding to the first file, the first pathname includes a first directory name and a second directory name that follows the first directory name, and the first pathname ends with a filename; determining that a data storage unit that stores a first attributes record corresponding to the first directory name is unavailable; responsive to the determining, performing a table look-up on one of the lookup tables using a sub-pathname of the pathname that includes the first and second directory names; locating a reference to a second attributes record corresponding to the sub-pathname, wherein the second attributes record is stored in the data storage unit that the lookup table from which the reference to the second attributes record is located is maintained in, wherein the plurality of data storage units includes a first storage unit configured in a first physical storage device that is accessible over a network and a second storage unit configured in a second physical storage device that is accessible over the network and is distinct from the first physical storage device.