Patent ID: 8943019
Filing Date: 2015-01-27
Classification: G06F

Abstract:
1. A method comprising: receiving a request to access a file from an application, wherein the request is received during a file system migration operation, the file system migration operation copies a plurality of files from a first file system to a second file system, and the plurality of files comprises the file; determining whether the file has been copied from the first file system to the second file system at the time the request is received; if the file has not been copied from the first file system to the second file system at the time the request is received, creating a pseudo vnode for the file, prior to creation of a vnode for the file, in the second file system, wherein the pseudo vnode includes information that enables the application to obtain the file from the first file system, and the pseudo vnode is created instead of copying the file from the first file system to the second file system at the time the request is received, creating an association between the pseudo vnode in the second file system and a vnode of the file at the first file system, wherein the association establishes a connection path between the pseudo vnode in the second file system and the vnode of the file at the first file system, and returning information identifying the pseudo vnode to the application, wherein the pseudo vnode and the association allow the application to locate and access the file in the first file system without having to create the file in the second file system, and the information identifying the pseudo vnode allows the application to perform an operation on the file at the first file system; if the file has been copied from the first file system to the second file system at the time the request is received, returning information identifying the file at the first and second file systems to the application, wherein the information identifying the file at the first and second file systems allows the application to perform the operation on the file at the first and second file systems; and copying an existing file from the first file system to the second file system when the existing file is closed at the first file system.