After a backup with the Continuous Data Protection for file product, the Remote Storage location contains the original file as well as an additional verison of the file with a .cdp extension
When Compression is enabled on Continuous Data Protection for Files along with Sub-File backup option on the Remote Storage settings page, the files stored on the Remote Storage will have two copies of the files. The first file will be the same as the original file backed up and other coppy with the .cdp extension.
If a file named compressed_file.txt is backed up on the remote storage then there will be two files available on the remote storage. The first file will be compresed_file.txt, which is the result of Sub-File backup option. The second file will be compressed_file.txt.cdp, which is the result of the Compression option selected.
As explained in the CDP for Files Deployment Guide.
If you enable both compression and sub-file copy, sub-file copy has precedence.
This means that a file which has a size larger than the minimum for sub-file copy
will not be compressed, since it is subject to sub-file copy activity. Only files
smaller than the minimum size for sub-file copy will be compressed.
Use sub-file copy check box
Check the box to turn on sub-file copy for remote backup copies.
Initially, an entire file is copied to the storage area. When sub-file copy is turned on, and when the file changes, only the changed information is copied to the storage area. The sub-file copies are saved as separate files on the remote storage.
Explanation about the compressed files.
Note: If a file is has been compressed by Tivoli Continuous Data Protection for Files, an additional suffix .cdp will be added to the original name of the file name, for example the local file name compressed_file.txt will become compressed_file.txt.cdp on the remote storage location
Thus we see two files on the Remote Storage location.