Managing file objects in a data storage system

• US 9,413,825 B2
• Filed: 10/31/2007
• Issued: 08/09/2016
• Est. Priority Date: 10/31/2007
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Oliveira, Fernando, Fridella, Stephen, Dimitrov, Rossen, Eaton, Patrick
• Primary Examiner(s): VU, BAI DUC
• Application Number:
  US11/981,624
• Publication Number:
  US 20090112880A1
• Time in Patent Office: 3,205 Days
• Field of Search: None
• 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, different from the metadata servers, 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;

wherein the metadata location server assigns a particular one of the metadata servers in connection with creation of a new file object.

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

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

4. The 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. The method, according to claim 1, wherein the file objects are provided with unique object identifiers.

6. The 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. The 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. The method, according to claim 7, wherein at least some of the metadata servers are provided with a unique subset of object identification values to assign to new file objects.

9. The method, according to claim 1, wherein assignment of the particular one of the metadata servers is random or is based on at least one of:

geographic proximity, load balancing, and a policy.

10. A Computer software, provided in a non-transitory 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, when executed by a processor, 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 different from the metadata servers, that, when executed by a processor, 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;

wherein the metadata location server assigns a particular one of the metadata servers in connection with creation of a new file object.

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

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

13. The Computer software, according to claim 11, 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.

14. The Computer software, according to claim 10, wherein the file objects are provided with unique object identifiers.

15. The Computer software, according to claim 14, 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.

16. The Computer software, according to claim 14, wherein at least some of the metadata servers maintain a table that correlates a subset of the object identification values with file objects.

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

18. The Computer software, according to claim 10, wherein assignment of the particular one of the metadata servers is random or is based on at least one of:

geographic proximity, load balancing, and a policy.

19. 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 different from the metadata servers, 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;

wherein the at least one metadata location server assigns a particular one of the metadata servers in connection with creation of a new file object.

20. The data storage system, according to claim 19, wherein the information for the subset of file objects includes a table having file identifiers and metadata location information.

21. The data storage system, according to claim 20, wherein the metadata location information points to data storage for a metadata object for a file.

22. The data storage system, according to claim 19, wherein the file objects are provided with unique object identifiers.

23. The data storage system, according to claim 22, 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.

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

25. The data storage system, according to claim 24, wherein at least some of the metadata servers are provided with a unique subset of object identification values to assign to new file objects.

26. The data storage system, according to claim 19, wherein assignment of the particular one of the metadata servers is random or is based on at least one of:

geographic proximity, load balancing, and a policy.