In-place preservation of file system objects during a disk clone operation

• US 7,480,682 B1
• Filed: 09/28/2007
• Issued: 01/20/2009
• Est. Priority Date: 02/10/2004
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Corporation (NortonLifeLock Inc.)
• Inventors: Pattinson, Nigel, Paxie, Andrew L., Haslam, Andrew Philip, Dowd, Abraham, Truell, Charles
• Primary Examiner(s): Le; Uyen T.
• Application Number:
  US11/864,536
• Time in Patent Office: 480 Days
• Field of Search: 707/204, 707/205, 711/162
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A cloning manager preserves in-place file system objects during a clone operation. The cloning manager determines boundaries of a file system to be created by the clone operation, and identifies at least one protected area within the boundaries, reserved for the file system. The cloning manager also identifies at least one in-place file system object within or overlapping the boundaries to be preserved during the clone operation. The cloning manager ensures that each object to be preserved is not located in a protected area, shifting the objects as necessary. The cloning manager creates the file system during the clone operation only in locations that do not contain objects to be preserved.

Claims

1. A computer implemented method for in-place preservation of file system objects during a clone operation, the method comprising the steps of:

determining boundaries on a target storage medium, the boundaries for containing a resultant file system;

identifying at least one in-place file system object at least partially within the boundaries, the in-place file system object comprising data on the target storage medium existing prior to the clone operation;

storing, in a location that will not be affected by the clone operation, metadata concerning each in-place file system object at least partially within the boundaries; and

performing the clone operation, the clone operation comprising creating the resultant file system only in locations within the boundaries in which no in-place file system object is located.

2. The method of claim 1, further comprising:

identifying at least one protected area within the boundaries; and

ensuring that each in-place file system object at least partially within the boundaries is not located in a protected area.

3. The method of claim 2 wherein ensuring that each in-place file system object at least partially within the boundaries is not located in a protected area comprises:

comparing a location of each in-place file system object at least partially within the boundaries to locations of identified protected areas; and

responsive to determining that a location of an in-place file system object conflicts with a location of a protected area, performing a step from a group of steps consisting of;

moving the conflicting in-place file system object to an available non-conflicting location, and updating metadata concerning the in-place file system object accordingly; and

classifying the result of the determination as an error condition.

4. The method of claim 1 wherein:

identifying at least one in-place file system object at least partially within the boundaries further comprises identifying at least one in-place file system object to be incorporated into the resultant file system created by the clone operation; and

wherein storing, in a location that will not be affected by the clone operation, metadata concerning each in-place file system object further comprises storing metadata concerning each identified in-place file system object to be incorporated into the resultant file system created by the clone operation, the metadata comprising at least one metadatum from a group of metadata consisting of;

an indication that the in-place file system object is to be incorporated in the resultant file system to be created by the clone operation;

a recovery path of the in-place file system object within the resultant file system to be created by the clone operation; and

a recovery partition of the in-place file system object within the resultant file system to be created by the clone operation.

5. The method of claim 4 further comprising:

for each identified in-place file system object to be incorporated into the resultant file system, determining whether its content is located within a location that is to be a data area of the resultant file system, and whether its location is aligned according to storage geometry of the resultant file system; and

responsive to determining that the location of at least one in-place file system object to be incorporated into the resultant file system is not compatible with the resultant file system, performing a step from a group of steps consisting of;

moving the in-place file system object such that its new location is compatible with the resultant file system and updating the associated metadata accordingly; and

classifying the result of the determination as an error condition.

6. The method of claim 4 further comprising performing the following additional steps after the clone operation:

using stored metadata to create a directory entry in the resultant file system for each identified in-place file system object to be incorporated into the resultant file system; and

updating metadata concerning the resultant file system to map the content location of each identified in-place file system object into the resultant file system.

7. The method of claim 1 wherein determining the boundaries comprises:

analyzing data concerning the clone operation to determine at least one attribute concerning the resultant file system to be created from a group of attributes consisting of;

a file system type of the resultant file system to be created;

a location of volume boundaries of the resultant file system to be created;

storage geometry concerning the resultant file system to be created; and

a number of total sectors to be used by the resultant file system to be created.

8. The method of claim 1 wherein the clone operation further comprises:

before allocating at least one sector for the creation of the resultant file system, checking the stored metadata concerning the in-place file system objects to determine if at least one in-place file system object is located at that location; and

responsive to determining that at least one in-place file system object is located at that location, allocating the at least one sector to the resultant file system at an available non-conflicting location.

9. A computer program product, comprising:

a computer-readable storage medium having executable computer program instructions recorded thereon for in-place preservation of file system objects during a clone operation, comprising;

program code for determining boundaries on a target storage medium, the boundaries for containing a resultant file system;

program code for identifying at least one in-place file system object at least partially within the boundaries, the in-place file system object comprising data on the target storage medium existing prior to the clone operation;

program code for storing, in a location that will not be affected by the clone operation, metadata concerning each in-place file system object at least partially within the boundaries; and

program code for performing the clone operation, the clone operation comprising creating the resultant file system only in locations within the boundaries in which no in-place file system object is located.

10. The computer program product of claim 9, further comprising:

program code for identifying at least one protected area within the boundaries; and

program code for ensuring that each in-place file system object at least partially within the boundaries is not located in a protected area.

11. The computer program product of claim 9, wherein the clone operation further comprises:

before allocating at least one sector for the creation of the resultant file system, checking the stored metadata concerning the in-place file system objects to determine if at least one in-place file system object is located at that location; and

responsive to determining that at least one in-place file system object is located at that location, allocating the at least one sector to the resultant file system at an available non-conflicting location.

12. The computer program product of claim 9 wherein:

the program code for identifying at least one in-place file system object at least partially within the boundaries further comprises program code for identifying at least one in-place file system object to be incorporated into the resultant file system created by the clone operation; and

wherein the program code for storing, in a location that will not be affected by the clone operation, metadata concerning each in-place file system object further comprises program code for storing metadata concerning each identified in-place file system object to be incorporated into the resultant file system created by the clone operation, the metadata comprising at least one metadatum from a group of metadata consisting of;

an indication that the in-place file system object is to be incorporated in the resultant file system to be created by the clone operation;

a recovery path of the in-place file system object within the resultant file system to be created by the clone operation; and

a recovery partition of the in-place file system object within the resultant file system to be created by the clone operation.

13. The computer program product of claim 12, further comprising:

program code for determining, for each identified in-place file system object to be incorporated into the resultant file system, whether its content is located within a location that is to be a data area of the resultant file system, and whether its location is aligned according to storage geometry of the resultant file system; and

at least one program code from a group of program codes consisting of;

program code for, responsive to determining that the location of at least one in-place file system object to be incorporated into the resultant file system is not compatible with the resultant file system, moving the in-place file system object such that its new location is compatible with the resultant file system and updating the associated metadata accordingly; and

program code for, responsive to determining that the location of at least one in-place file system object to be incorporated into the file system is not compatible with the file system, classifying the result of the determination as an error condition.

14. The computer program product of claim 12, further comprising:

program code for using stored metadata to create a directory entry in the resultant file system for each identified in-place file system object to be incorporated into the resultant file system; and

program code for updating metadata concerning the resultant file system to map the content location of each identified in-place file system object into the resultant file system.

15. A computer system for in-place preservation of file system objects during a clone operation, comprising:

a processor for executing computer program modules; and

a computer-readable storage medium storing executable computer program modules comprising;

a software portion configured to determine boundaries on a target storage medium, the boundaries for containing a resultant file system;

a software portion configured to identify at least one in-place file system object at least partially within the boundaries, the in-place file system object comprising data on the target storage medium existing prior to the clone operation;

a software portion configured to store, in a location that will not be affected by the clone operation, metadata concerning each in-place file system object at least partially within the boundaries; and

a software portion configured to perform the clone operation, the clone operation comprising creating the resultant file system only in locations within the boundaries in which no in-place file system object is located.

16. The computer system of claim 15, further comprising:

a software portion configured to identify at least one protected area within the boundaries; and

a software portion configured to ensure that each in-place file system object at least partially within the boundaries is not located in a protected area.

17. The computer system of claim 15 wherein the clone operation further comprises:

before allocating at least one sector for the creation of the resultant file system, checking the stored metadata concerning the in-place file system objects to determine if at least one in-place file system object is located at that location; and

responsive to determining that at least one in-place file system object is located at that location, allocating the at least one sector to the resultant file system at an available non-conflicting location.

18. The computer system of claim 15 wherein:

the software portion configured to identify at least one in-place file system object at least partially within the boundaries further comprises a software portion configured to identify at least one in-place file system object to be incorporated into the resultant file system created by the clone operation; and

wherein the software portion configured to store, in a location that will not be affected by the clone operation, metadata concerning each in-place file system object further comprises a software portion configured to store metadata concerning each identified in-place file system object to be incorporated into the resultant file system created by the clone operation, the metadata comprising at least one metadatum from a group of metadata consisting of;

an indication that the in-place file system object is to be incorporated in the resultant file system to be created by the clone operation;

a recovery path of the in-place file system object within the resultant file system to be created by the clone operation; and

a recovery partition of the in-place file system object within the resultant file system to be created by the clone operation.

19. The computer system of claim 18 further comprising:

a software portion configured to determine, for each identified in-place file system object to be incorporated into the resultant file system, whether its content is located within a location that is to be a data area of the resultant file system, and whether its location is aligned according to storage geometry of the resultant file system; and

at least one software portion from a group of software portions consisting of;

a software portion configured to move, responsive to determining that the location of at least one in-place file system object to be incorporated into the resultant file system is not compatible with the resultant file system, the in-place file system object such that its new location is compatible with the resultant file system and updating the associated metadata accordingly; and

a software portion configured to classify, responsive to determining that the location of at least one in-place file system object to be incorporated into the resultant file system is not compatible with the resultant file system, the result of the determination as an error condition.

20. The computer system of claim 18 further comprising:

a software portion configured to use stored metadata to create a directory entry in the resultant file system for each identified in-place file system object to be incorporated into the resultant file system; and

a software portion configured to update metadata concerning the resultant file system to map the content location of each identified in-place file system object into the resultant file system.