When a write operation is performed on a very large file (more than 100 gigabytes [GB]) that is stored on a data-deduplication-enabled volume in Windows Server 2012 or Windows Server 2012 R2, the write operation fails. Additionally, you receive the following error message:
Note When the issue occurs, the file goes into a maximum fragmentation state, and no data deduplication mechanism can repair the file.
This problem occurs because the NT file system (NTFS) reached the maximum number of extents. When the limit is reached, NTFS returns the ERROR_FILE_SYSTEM_LIMITATION error message.
To resolve the problem, follow these steps:
Run Defrag on the volume on which this problem occurs. For more information, see Defrag.
If the problem continues to occur, follow these steps:
Copy the file to a new file.
Delete the original file.
Rename the new file by using the original file name.
Optimize the new file.
Some best practices for data deduplication:
If you plan to use very large files (more than 500 GB) that have many in-place chunks, you should format the volume by using the "/L" option to accommodate large-size file records. By default, the volume is formatted to use small-size file records.
After data deduplication is performed on a volume for the first time, you should perform a full backup immediately afterward.
Perform garbage-collection jobs weekly on the chunk store to remove chunks that are no longer used.
After a garbage-collection job is finished, you should perform a full backup on the volume. You should do this because the garbage-collection job may result in many changes in the chunk store if many files were deleted after the last garbage-collection job.