Avoiding compression of high-entropy data during creation of a backup of a source storage

1. A method for avoiding compression of high-entropy data during creation of a backup of a source storage, the method comprising:

identifying a chunk in a file in a source storage, the file having a file type, the chunk having an original size;

compressing, during creation of a backup of the source storage, the chunk to generate a compressed chunk, the compressed chunk having a compressed size;

determining a compression ratio for the chunk by comparing the original size to the compressed size;

determining whether the compression ratio is less than a compression threshold; and

in response to determining that the compression ratio is less than the compression threshold, automatically designating the file type as a high-entropy file type and automatically avoiding compression, during the creation of the backup, of chunks in a second file in the source storage having the file type.

2. The method as recited in claim 1 , wherein the identifying includes identifying the file to which the chunk belongs after the determining that the compression ratio is less than the compression threshold.

3. The method as recited in claim 1 , wherein the file type of the file is designated by a file extension of the file.

4. The method as recited in claim 3 , wherein the automatically designating includes automatically adding the file extension to a compression exclusion list.

5. The method as recited in claim 1 , wherein the file type of the file is designated by a file name of the file.

6. The method as recited in claim 5 , wherein the automatically designating includes automatically adding the file name to a compression exclusion list.

7. The method as recited in claim 1 , further comprising:

in response to determining that the compression ratio is less than the compression threshold, automatically avoiding compression, during creation of the backup of the source storage, of additional chunks in the file.

8. The method as recited in claim 1 , further comprising:

in response to determining that the compression ratio is less than the compression threshold, automatically avoiding compression, during creation of a second backup of a second source storage, of chunks in any files in the second source storage having the file type.

9. The method as recited in claim 1 , wherein:

the automatically designating and the automatically avoiding are further performed in response to also determining that compression ratios of a threshold number of additional chunks in one or more files in the source storage having the file type are also less than the compression threshold.

10. The method as recited in claim 1 , wherein:

the automatically designating and the automatically avoiding are further performed in response to also determining that compression ratios of chunks in a threshold number of additional files in the source storage having the file type are also less than the compression threshold.

11. One or more non-transitory computer-readable media storing one or more programs that are configured, when executed, to cause one or more processors to execute the method as recited in claim 1 .

12. A method for avoiding compression of high-entropy data during creation of a backup of a source storage, the method comprising:

identifying a chunk in a file in a source storage, the file having a file extension, the chunk having an original size;

compressing, during creation of a backup of the source storage, the chunk to generate a compressed chunk, the compressed chunk having a compressed size;

determining a compression ratio for the chunk by comparing the original size to the compressed size;

determining whether the compression ratio is less than a compression threshold; and

in response to determining that the compression ratio is less than the compression threshold, automatically designating the file extension as a high-entropy file extension and automatically avoiding compression, during the creation of the backup, of chunks in a second file in the source storage having the file extension.

13. The method as recited in claim 12 , wherein:

the backup is an image-based backup of the source storage; and

the identifying includes identifying the file to which the chunk belongs after the determining that the compression ratio is less than the compression threshold.

14. The method as recited in claim 12 , wherein the backup is a file-based backup of the source storage.

15. The method as recited in claim 12 , wherein the automatically designating includes adding the file extension to a compression exclusion list.

16. The method as recited in claim 12 , further comprising:

in response to determining that the compression ratio is less than the compression threshold, automatically avoiding compression, during creation of the backup of the source storage, of additional chunks in the file.

17. The method as recited in claim 12 , further comprising:

in response to determining that the compression ratio is less than the compression threshold, automatically avoiding compression, during creation of a second backup of a second source storage, of chunks in any files in the second source storage having the file extension.

18. The method as recited in claim 12 , wherein:

the automatically designating and the automatically avoiding are further performed in response to also determining that compression ratios of a threshold number of additional chunks in one or more files in the source storage having the file extension are also less than the compression threshold.

19. The method as recited in claim 12 , wherein:

the automatically designating and the automatically avoiding are further performed in response to also determining that compression ratios of chunks in a threshold number of additional files in the source storage having the file extension are also less than the compression threshold.

20. One or more non-transitory computer-readable media storing one or more programs that are configured, when executed, to cause one or more processors to execute the method as recited in claim 12 .