Managing file objects in a data storage system

• US 20090112880A1
• Filed: 10/31/2007
• Published: 04/30/2009
• Est. Priority Date: 10/31/2007
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Fridella, Stephen, Dimitrov, Rossen, Oliveira, Fernando, Eaton, Patrick
• Granted Patent: US 9,413,825 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• 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

Managing file objects in a data storage system includes providing a plurality of metadata servers, each metadata server having information for only a subset of file objects in the storage system, each subset for each of the metadata servers being less than a total number of file objects for the system and includes providing at least one metadata location server, where an entity accessing a specific file object of the system determines which of the metadata servers contains data for the specific file object by first accessing the at least one metadata location server. Information for the subset of file objects may include a table having file identifiers and metadata location information. The metadata location information may point to data storage for a metadata object for a file.

Claims

1. A method of managing file objects in a data storage system, comprising:

providing a plurality of metadata servers, each metadata server having information for only a subset of file objects in the storage system, each subset for each of the metadata servers being less than a total number of file objects for the system; and

providing at least one metadata location server, wherein an entity accessing a specific file object of the system determines which of the metadata servers contains data for the specific file object by first accessing the at least one metadata location server.

2. A method, according to claim 1, wherein information for the subset of file objects includes a table having file identifiers and metadata location information.

3. A method, according to claim 2, wherein the metadata location information points to data storage for a metadata object for a file.

4. A method, according to claim 2, wherein the table also includes lease information that indicates entities that have read permission for the file object and entities that have write permission for the file object.

5. A method, according to claim 1, wherein file objects are provided with unique object identifiers.

6. A method, according to claim 5, wherein the at least one metadata location server determines an appropriate metadata server to use for a file object according to an object identification value for the file object.

7. A method, according to claim 5, wherein at least some of the metadata servers maintain a table that correlates a subset of the object identification values with file objects.

8. A method, according to claim 7, wherein at least some of the metadata servers are provided with a unique subset of object identification values for assigning to new file objects.

9. Computer software, provided in a computer-readable medium, that manages file objects in a data storage system, the software comprising:

executable code, provided on a plurality of metadata servers, that maintains information for only a subset of file objects in the storage system, each subset for each of the metadata servers being less than a total number of file objects for the system; and

executable code, provided on at least one metadata location server, that provides an indication of which of the metadata servers contains data for a specific file object in response to a request therefor provided to the at least one metadata server.

10. Computer software, according to claim 9, wherein information for the subset of file objects includes a table having file identifiers and metadata location information.

11. Computer software, according to claim 10, wherein the metadata location information points to data storage for a metadata object for a file.

12. Computer software, according to claim 10, wherein the table also includes lease information that indicates entities that have read permission for the file object and entities that have write permission for the file object.

13. Computer software, according to claim 9, wherein file objects are provided with unique object identifiers.

14. Computer software, according to claim 13, wherein the at least one metadata location server includes executable code that determines an appropriate metadata server to use for a file object according to an object identification value for the file object.

15. Computer software, according to claim 13, wherein at least some of the metadata servers maintain a table that correlates a subset of the object identification values with file objects.

16. Computer software, according to claim 15, wherein at least some of the metadata servers are provided with a unique subset of object identification values for assigning to new file objects.

17. A data storage system, comprising:

a plurality of clients that access file objects of the storage system; and

a plurality of interconnected servers coupled to the clients, the servers including a plurality of metadata servers, each metadata server having information for only a subset of file objects in the storage system, each subset for each of the metadata servers being less than a total number of file objects for the system, the servers also including at least one metadata location server, wherein a client accessing a specific file object of the system determines which of the metadata servers contains data for the specific file object by first accessing the at least one metadata location server.

18. A data storage system, according to claim 17, wherein information for the subset of file objects includes a table having file identifiers and metadata location information.

19. A data storage system, according to claim 18, wherein the metadata location information points to data storage for a metadata object for a file.

20. A data storage system, according to claim 17, wherein file objects are provided with unique object identifiers.

21. A data storage system, according to claim 20, wherein the at least one metadata location server determines an appropriate metadata server to use for a file object according to an object identification value for the file objects for the file.

22. A data storage system, according to claim 20, wherein at least some of the metadata servers maintain a table that correlates a subset of the object identification values with file objects.

23. A data storage system, according to claim 22, wherein at least some of the metadata servers are provided with a unique subset of object identification values for assigning to new file objects.

24. A method of managing file objects in a data storage system, comprising:

providing a plurality of a first type of server, each having information for only a subset of file objects in the storage system; and

providing at least one of a second type of server that provides information indicating which of the servers of the first type contains data for a specific file object by first accessing the at least one server of the second type.

25. A data storage system, comprising:

a plurality of clients that access file objects of the storage system; and

a plurality of interconnected servers coupled to the clients, the servers including a plurality of metadata servers, each metadata server having information for only a subset of file objects in the storage system, each subset for each of the metadata servers being less than a total number of file objects for the system, the servers also including at least one metadata location server, wherein a client accessing a specific file of the system determines which of the metadata servers contains data for the specific file object by first accessing the at least one metadata location server.