MIGRATION OF CONTROL IN A DISTRIBUTED SEGMENTED FILE SYSTEM

• US 20070226331A1
• Filed: 05/30/2007
• Published: 09/27/2007
• Est. Priority Date: 09/12/2000
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: IBRIX, Inc. (HP Inc.)
• Inventors: Orszag, Steven A., SRINIVASAN, Sudhir
• Granted Patent: US 7,769,711 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067
• CPC Class Codes: G06F 16/954 Navigation, e.g. using categorised browsing
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A method of managing segments in a distributed-file system implemented by a plurality of file servers includes determining a segment of the distributed-file system controlled by a first file server for which control is to be migrated, selecting a second file server, that is different from the first file server, to take control of the segment, and moving control of the segment from the first file server to the second file server.

Claims

1. A method of using an administrator device to manage a distributed, segmented single file system implemented by a plurality of file servers that are configured to control metadata of separate segments of the single file system, the single file system including file system entities residing in the segments and comprising at least portions of one of files and directories, the method comprising:

sending a control-migration signal from the administrator to a first file server that controls a particular segment of the file system and to a second file server that is to take control of the particular segment, the control-migration signal indicating to the first file server to stop controlling the particular segment and indicating to the second file server to start controlling the particular segment; and

sending an allow-access signal from the administrator to the second file server indicating to the second file server to allow access to the particular segment;

wherein access to the particular segment by the second file server is allowed only after the first file server stops controlling the particular segment.

2. The method of claim 1 wherein the administrator sends the allow-access signal only after control migration of the particular segment caused by the control-migration signal is complete.

3. The method of claim 1 wherein the control-migration signal causes a change in at least one association of file servers and segments in the first and second file servers.

4. The method of claim 3 wherein the change comprises a modification of a mapping of segments and file servers.

5. The method of claim 4 wherein the change comprises one of an editing of the mapping of segments and file servers and a replacing of the mapping of segments and file servers.

6. The method of claim 3 wherein the change occurs in the at least one association in both the first and second file servers at substantially the same time.

7. The method of claim 6 wherein sending the control-migration signal comprises sending the control-migration signal to each of the file servers implementing the file system, and wherein the control-migration signal causes changes in at least one association of segments and file servers in file servers other than the first and second file servers at least a second time, after the first time.

8. A method of processing a file segment access request in a distributed, segmented single file system implemented by a plurality of file servers that are configured to control metadata of separate segments of the single file system, the single file system including file system entities residing in the segments and comprising at least portions of one of files and directories, the method comprising:

transmitting a file segment access request, from a requesting device to a selected file server of the plurality of file servers, requesting access to a particular segment of the single file system;

receiving the file segment access request at the selected file server from the requesting device, the single file system including a root directory and being organized such that any file or directory of the single file system can be accessed by traversing the single file system starting from the root directory, the file segment request corresponding to a first association of file system segments and the plurality of file servers stored by the requesting server, the selected file server storing a second association of file system segments and the plurality of file servers; and

rejecting the file segment access request at the selected file server, without indicating which file server controls the particular segment, if the first and second associations differ with respect to which file server controls the particular segment.

9. The method of claim 8 further comprising:

if the second association is older than the first association, then;

obtaining a first updated association of file system segments and the plurality of file servers by the selected file server; and

processing the request by the selected file server in accordance with the first updated association; and

if the second association is newer than the first association, then;

obtaining a second updated association of file system segments and the plurality of file servers by the requesting server; and

processing the request by the requesting device in accordance with the second updated association.