Global namespace for a hierarchical set of file systems

• US 10,579,598 B2
• Filed: 01/03/2017
• Issued: 03/03/2020
• Est. Priority Date: 01/03/2017
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bhagwat, Deepavali M., Eshel, Marc, Hildebrand, Dean, Naik, Manoj P., Sawdon, Wayne A., Schmuck, Frank B., Tewari, Renu
• Primary Examiner(s): Morrison, Jay A
• Application Number:
  US15/397,652
• Publication Number:
  US 20180189305A1
• Time in Patent Office: 1,155 Days
• CPC Class Codes: G06F 16/122 using management policies backup systems G06F11/1446; file migration policies for HSM systems G06F16/185
• CPC Class Codes: G06F 16/185 Hierarchical storage management [HSM] systems, e.g. file migration or policies thereof details of archiving G06F16/11

Abstract

One embodiment provides a method for storage management in a hierarchical file system. The method includes tracking directories for sub-file systems of the hierarchical file system. A request for creation of an additional directory in the hierarchical file system is received. In response to the request, the additional directory is created in a sub-file system of the hierarchical file system while providing that each directory resides in only one sub-file system. If the additional directory is a child directory, the additional directory is created in the sub-file system containing the parent directory of the child directory.

Claims

1. A method for storage management in a hierarchical set of file systems, the method comprising:

creating a structure for the hierarchical set of file systems including a top-file system and sub-file systems that each include files and directories;

tracking directories for sub-file systems of the hierarchical set of file systems;

receiving a request to create an additional directory;

creating, based on applying a directory creation policy, the additional directory in a sub-file system of the hierarchical set of file systems while providing that each directory resides in only one sub-file system; and

upon a request by a particular sub-file system for more inodes without any inodes available, revoking inode numbers from at least one other sub-file system having unused inodes;

wherein failure in one sub-file system has no affect on other sub-file systems in the hierarchical set of file systems, and each directory in the sub-file systems is named using an inode number of a directory.

2. The method of claim 1, wherein:

applying the directory creation policy comprises;

selecting a sub-file system with the largest available space upon determining that the additional directory is a parent directory in the top-file system; and

a namespace in the top file system and pointers to each of the multiple sub-file systems include a name of a directory in a sub-file system that is its inode number in the top file system portion.

3. The method of claim 1, wherein applying the directory creation policy comprises:

selecting a sub-file system having available space at least as large as an estimated size requirement for the additional directory upon determining that the additional directory is a parent directory in the top-file system.

4. The method of claim 1, wherein applying the directory creation policy comprises:

selecting, in a round-robin fashion, a sub-file system having available space for the additional directory upon determining that the additional directory is a parent directory in the top-file system.

5. The method of claim 1, wherein applying the directory creation policy comprises:

selecting a sub-file system containing a parent directory of the child directory upon determining that the additional directory is a child directory.

6. The method of claim 1, wherein tracking comprises:

for each directory in a sub-file system;

maintaining a corresponding directory in a top-file system; and

maintaining a symbolic pointer in the corresponding directory which points from the corresponding directory to the sub-file system where the tracked directory resides.

7. The method of claim 5, further comprising:

creating a corresponding directory in the top-file system;

creating a symbolic pointer in the corresponding directory in the top-file system which points from the corresponding directory to the particular sub-file system containing the additional directory; and

parallelizing file system operations by issuing the file system operations on any number of sub-file systems simultaneously.

8. The method of claim 7, wherein directories are stored at a root for the sub-file systems.

9. A computer program product for storage management in a hierarchical set of file systems, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to:

create, by the processor, a structure for the hierarchical set of file systems including a top-file system and sub-file systems that each include files and directories;

track, by the processor, directories for sub-file systems of the hierarchical set of file systems;

receive, by the processor, a request to create an additional directory;

create, based on applying a directory creation policy by the processor, the additional directory in a sub-file system of the hierarchical set of file systems while providing that each directory resides in only one sub-file system; and

upon a request by a particular sub-file system for more inodes without any inodes available, revoke, by the processor, inode numbers from at least one other sub-file system having unused inodes;

wherein failure in one sub-file system has no affect on other sub-file systems in the hierarchical set of file systems, and each directory in the sub-file systems is named using an inode number of a directory.

10. The computer program product of claim 9, wherein:

applying the directory creation policy further comprising program instructions executable by the processor to cause the processor to;

select, by the processor, a sub-file system with the largest available space upon determining that the additional directory is a parent directory in the top-file system; and

a namespace in the top file system and pointers to each of the multiple sub-file systems include a name of a directory in a sub-file system that is its inode number in the top file system portion.

11. The computer program product of claim 9, wherein applying the directory creation policy further comprising program instructions executable by the processor to cause the processor to:

select, by the processor, a sub-file system having available space at least as large as an estimated size requirement for the additional directory upon determining that the additional directory is a parent directory in the top-file system.

12. The computer program product of claim 9, wherein applying the directory creation policy further comprising program instructions executable by the processor to cause the processor to:

select, by the processor, in a round-robin fashion, a sub-file system having available space for the additional directory upon determining that the additional directory is a parent directory in the top-file system.

13. The computer program product of claim 9, wherein applying the directory creation policy further comprising program instructions executable by the processor to cause the processor to:

select, by the processor, a sub-file system containing a parent directory of the child directory upon determining that the additional directory is a child directory.

14. The computer program product of claim 13, further comprising program instructions executable by the processor to cause the processor to:

create, by the processor, a corresponding directory in the top-file system;

create, by the processor, a symbolic pointer in the corresponding directory in the top-file system which points from the corresponding directory to the particular sub-file system containing the additional directory; and

parallelize, by the processor, file system operations by issuing the file system operations on any number of sub-file systems simultaneously.

15. The computer program product of claim 13, further comprising program instructions executable by the processor to cause the processor to:

maintain, by the processor, a corresponding directory in a top-file system; and

maintain, by the processor, a symbolic pointer in the corresponding directory which points from the corresponding directory to the sub-file system where the tracked directory resides.

16. The computer program product of claim 15, wherein directories are stored at a root for the sub-file systems.

17. An apparatus comprising:

a memory storing instructions; and

one or more processors executing the instructions to;

create a structure for a hierarchical set of file systems including a top-file system and sub-file systems that each include files and directories;

track directories for sub-file systems of the hierarchical set of file systems;

receive a request to create an additional directory;

create, based on applying a directory creation policy, the additional directory in a sub-file system of the hierarchical set of file systems while providing that each directory resides in only one sub-file system; and

upon a request by a particular sub-file system for more inodes without any inodes available, revoke inode numbers from at least one other sub-file system having unused inodes;

wherein failure in one sub-file system has no affect on other sub-file systems in the hierarchical set of file systems, and each directory in the sub-file systems is named using an inode number of a directory.

18. The apparatus of claim 17, wherein the one or more processors further execute instructions to:

create a corresponding directory in the top-file system;

create a symbolic pointer in the corresponding directory in the top-file system which points from the corresponding directory to the particular sub-file system containing the additional directory; and

parallelize file system operations by issuing the file system operations on any number of sub-file systems simultaneously;

wherein applying the directory creation policy comprises;

selecting a sub-file system containing a parent directory of the child directory upon determining that the additional directory is a child directory.

19. The apparatus of claim 18, wherein directories are stored at a root for the sub-file systems, and a namespace in the top file system and pointers to each of the multiple sub-file systems include a name of a directory in a sub-file system that is its inode number in the top file system portion.