PERSISTENT FILE REPLACEMENT MECHANISM

• US 20120066274A1
• Filed: 09/09/2010
• Published: 03/15/2012
• Est. Priority Date: 09/09/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Stephenson, Marc J.
• Granted Patent: US 8,620,974 B2
• Time in Patent Office: Days
• US Class Current: 707/825
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors

Abstract

An original file of a versioned WPAR, that are incompatible with a global operating system, can be persistently replaced with a corresponding replacement file that is compatible with the global operating system. For this, the original file can be renamed and a symbolic link file can be created to reference the replacement file instead of the original file. A software maintenance program can also be persistently replaced to preserve the replacement file and to maintain compatibility with the global operating system regardless of new instances of the original file delivered by the software maintenance program. The replacement file that corresponds to the original file can be identified and renamed. In response to detecting a new version of the original file, the new version of the original file can be renamed. A reference to the new version of the original file can be updated to reference the replacement file.

Claims

1. A method for maintaining a replacement file that persistently replaces a corresponding original file, the method comprising:

identifying, within a virtual operating system instance associated with an earlier version of an operating system, the replacement file that corresponds to the original file of the virtual operating system instance, wherein the earlier version of the operating system is earlier than a later version of the operating system associated with a kernel that supports the virtual operating system instance;

in response to detecting an updated original file, renaming the updated original file of the virtual operating system instance; and

replacing a first reference to the updated original file with a second reference to the replacement file.

2. The method of claim 1, wherein the replacement file is associated with the later version of the operating system associated with the kernel.

3. The method of claim 1, further comprising:

temporarily replacing the replacement file with the original file in response to determining that the original file of the virtual operating system instance will be altered by software maintenance procedures executed within the virtual operating system instance.

4. The method of claim 3, wherein said replacing the replacement file with the original file comprises one of:

updating a symbolic link file that references the replacement file to reference the corresponding original file of the virtual operating system instance, and

replacing a symbolic link file that references the replacement file with the original file of the virtual operating system instance.

5. The method of claim 1, wherein said identifying the replacement file that corresponds to the original file of the virtual operating system instance is in response to:

determining that the original file of the virtual operating system instance will be altered by software maintenance procedures executed within the virtual operating system instance.

6. The method of claim 5, wherein the updated original file is generated in response to the software maintenance procedures executed within the virtual operating system instance.

7. The method of claim 6, wherein said identifying the replacement file that corresponds to the original file of the virtual operating system instance further comprises:

identifying one or more original files of the virtual operating system instance that will be altered in response to the software maintenance procedures, wherein the one or more original files of the virtual operating system instance comprise the original file;

for each of the one or more original files of the virtual operating system instance,

determining whether the original file was persistently replaced with a corresponding replacement file associated with the later version of the operating system associated with the kernel.

8. The method of claim 7, wherein the one or more original files comprise a software maintenance program and wherein a replacement file that corresponds to the software maintenance program is configured for maintaining each replacement file that persistently replaces corresponding ones of the one or more original files following the software maintenance procedures executed within the virtual operating system instance.

9. The method of claim 1, further comprising:

accessing a replacement database to identify one or more original files of the virtual operating system instance that are to be persistently replaced with corresponding ones of replacement files associated with the later version of the operating system associated with the kernel, wherein the one or more original files comprise the original file and wherein the corresponding ones of the replacement files comprise the replacement file;

for each of the one or more original files of the virtual operating system instance that are to be persistently replaced,

renaming the original file of the virtual operating system instance; and

replacing the original file of the virtual operating system instance with the corresponding replacement file.

10. The method of claim 9, wherein said replacing, for each of the one or more original files of the virtual operating system instance that are to be persistently replaced, the original file of the virtual operating system instance with the corresponding replacement file comprises one of:

for each of the one or more original files of the virtual operating system instance that are to be persistently replaced,

creating a symbolic link file to reference the replacement file that corresponds to the original file of the virtual operating system instance, and

replacing the original file of the virtual operating system instance with a symbolic link file that references the replacement file that corresponds to the original file.

11. A computer program product for persistent file replacement, the computer program product comprising:

a computer readable storage medium having computer usable program code embodied therewith, the computer readable program code configured to,

identify, within a virtual operating system instance associated with an earlier version of an operating system, the replacement file that corresponds to the original file of the virtual operating system instance, wherein the earlier version of the operating system is earlier than a later version of the operating system associated with a kernel that supports the virtual operating system instance;

in response to detecting an updated original file, rename the updated original file of the virtual operating system instance; and

replace a first reference to the updated original file with a second reference to the replacement file.

12. The computer program product of claim 11, wherein the replacement file is associated with the later version of the operating system associated with the kernel.

13. The computer program product of claim 11, wherein the computer readable program code configured to:

temporarily replace the replacement file with the original file in response to the computer readable program code determining that the original file of the virtual operating system instance will be altered by software maintenance procedures executed within the virtual operating system instance.

14. The computer program product of claim 11, wherein the computer readable program code configured to identify the replacement file that corresponds to the original file of the virtual operating system instance comprises the computer readable program code configured to:

determine that the original file of the virtual operating system instance will be altered by software maintenance procedures executed within the virtual operating system instance.

15. The computer program product of claim 14, wherein the computer readable program code configured to identify the replacement file that corresponds to the original file of the virtual operating system instance further comprises the computer readable program code configured to:

identify one or more original files of the virtual operating system instance that will be altered in response to the software maintenance procedures, wherein the one or more original files of the virtual operating system instance comprise the original file;

for each of the one or more original files of the virtual operating system instance,

determine whether the original file was persistently replaced with a corresponding replacement file associated with the later version of the operating system associated with the kernel.

16. The computer program product of claim 11, wherein the computer readable program code is further configured to:

access a replacement database to identify one or more original files of the virtual operating system instance that are to be persistently replaced with corresponding ones of replacement files associated with the later version of the operating system associated with the kernel, wherein the one or more original files comprise the original file and wherein the corresponding ones of the replacement files comprise the replacement file;

for each of the one or more original files of the virtual operating system instance that are to be persistently replaced,

rename the original file of the virtual operating system instance; and

replace the original file of the virtual operating system instance with the corresponding replacement file.

17. A system for maintaining a replacement file that persistently replaces a corresponding original file, the system comprising:

a processor;

a network interface coupled with the processor; and

a file replacement unit coupled with the processor and with the network interface, the file replacement unit operable to;

identify, within a virtual operating system instance associated with an earlier version of an operating system, the replacement file that corresponds to the original file of the virtual operating system instance, wherein the earlier version of the operating system is earlier than a later version of the operating system associated with a kernel that supports the virtual operating system instance;

in response to detecting an updated original file, rename the updated original file of the virtual operating system instance; and

replace a first reference to the updated original file with a second reference to the replacement file.

18. The system of claim 17, wherein the file replacement unit is further operable to:

temporarily replace the replacement file with the original file in response to the file replacement unit determining that the original file of the virtual operating system instance will be altered by software maintenance procedures executed within the virtual operating system instance and,

wherein the file replacement unit operable to identify the replacement file that corresponds to the original file of the virtual operating system instance is in response to the file replacement unit determining that the original file of the virtual operating system instance will be altered by software maintenance procedures executed within the virtual operating system instance.

19. The system of claim 18, wherein the updated original file is generated in response to the software maintenance procedures executed within the virtual operating system instance.

20. The system of claim 17, wherein the file replacement unit comprises the computer readable storage medium.