Method and apparatus for file backup
A file backup method, which can be implemented on a virtual machine system or applied to backup files of a virtual machine, is herein described. The virtual machine system may include a virtual machine server and be associated with a backup server. Changes to a storage media are tracked through change block tracking. A location where file system records reside on the storage media is identified. Changed file system records are identified among the tracked changes to the storage media. Copies are made of the files that the changed file system records are pointing to.
1. A file backup method, comprising:
receiving a listing of changed blocks, wherein the listing of changed blocks identifies a storage media location for each change;
identifying a file system type for file system records residing on the storage media;
identifying a location where the file system records reside on the storage media based on the identified file system type;
comparing the storage media location for each change with the location where file system records reside; and
examining the changed file system records based on the comparing to determine which files should to include in the file backup, the examining comprising:
identifying an intersection between the location where file system records reside and the listing of changed blocks; and
sorting among the changed file system records and unchanged data at the identified intersection.
2. The file backup method of claim 1 , wherein the method comprises:
providing an identifier representing a time point for a most recent full backup of the storage media.
3. The file backup method of claim 2 , wherein the identifier is a timestamp.
4. The file backup method of claim 1 , wherein the storage media is integrated into a virtualized storage environment.
5. The file backup method of claim 1 , wherein the storage media includes a virtual disk of a virtual machine.
6. The file backup method of claim 1 , wherein:
identifying the location where the file system records reside includes reading one of master file table or inodes.
7. The file backup method of claim 1 , wherein the identifying the file system type includes parsing the file system.
8. The file backup method of claim 1 , wherein the identifying the file system type includes mounting the file system.
9. The file backup method of claim 1 , wherein the copying is one of a differential backup or an incremental backup from a most recent full backup of the storage media.
10. The file backup method of claim 1 , further comprising backing up the determined changed file system records.
11. A non-transitory computer readable medium containing instructions for causing
a computer to perform a method, the method comprising:
receiving a listing of changed blocks, wherein the listing of changed blocks identifies a storage media location for each change;
identifying a file system type for file system records residing on the storage media;
identifying a location where the file system records reside on the storage media based on the identified file system type;
comparing the storage media location for each change with the location where file system records reside; and
examining the changed file system records based on the comparing to determine which files should to include in the file backup, the examining comprising:
identifying an intersection between the location where file system records reside and the listing of changed blocks; and
sorting among the changed file system records and unchanged data at the identified intersection.
12. The medium of claim 11 , wherein the method comprises:
providing an identifier representing a time point for a most recent full backup of the storage media.
13. The medium of claim 12 , wherein the identifier is a timestamp.
14. The medium of claim 11 , wherein the storage media is integrated into a virtualized storage environment.
15. The medium of claim 11 , wherein the storage media includes a virtual disk of a virtual machine.
16. The medium of claim 11 , wherein:
identifying the location where the file system records reside includes reading one of master file table or inodes.
17. The medium of claim 11 , wherein the identifying the file system type includes parsing the file system.
18. The medium of claim 11 , wherein the identifying the file system type includes mounting the file system.
19. The medium of claim 11 , wherein the copying is one of a differential backup or an incremental backup from a most recent full backup of the storage media.
20. The medium of claim 11 , wherein the method further comprises backing up the determined changed file system records.