TL;DR: do backup software replicate the EFS encryption on destination?

I'm backuping: D:\Documents\ (from a 1 TB hard drive's main folder, NTFS)

to: I:\BackupDocuments\ (on a 1 TB external USB hard drive, NTFS)


xxcopy "D:\Documents\" "I:\BackupDocuments\" /clone /ff-3602 /jj0 /pz0 /pb 

Certain subfolders (but not all of them) of D:\Documents\ are EFS-encrypted (easy to do and nearly transaprent encryption available in Windows 7).

Problem: only ~ 1 every 10 encrypted subfolders are encrypted in the destination (visible in green in the Windows Explorer).

Also, let's say the D:\Documents\Test\ fully-encrypted folder contains 500 files. Then only a few (randomly chosen among the 500!) files are encrypted in the destination I:\BackupDocuments\Test. That's really strange.

Note: I also tried with another backuping software (SyncBack), and it seems to be the same problem.

Question: Is that a general problem when backuping a drive containing certain encrypted folders, that the encryption is not always replicated on destination (sometimes true, sometimes false, randomly)?

Edit: I've done additional tests:

  • Copying directly with Windows Explorer (Copy/Paste) result in keeping encryption on destination

  • I did a new test with destination disk initially empty, then xxcopy will not replicate encryption at all to destination

  • I did a new test with destination disk initially empty, then SyncBack (backup software) will replicate encryption to destination for all files

  • I did a test with destination = exact backup of source, except that encryption is on on all source files, and encryption is off on all destination files. Then running a SyncBack backup will cause overwrite of the destination to have encryption on (that's good!) for most files (.MP3, etc.), but not all files (.URL files are untouched, left unencrypted on destination).

  • Are you saying that when you perform your copy operations the results you're getting are indeed random? – I say Reinstate Monica Oct 20 '17 at 1:05
  • 1
    I mean: if all 500 files of a folder are efs-encrypted on source, then after backup, only a few of them (that seem randomly selected!) appear as encrypted on destination (external hard drive). – Basj Oct 20 '17 at 6:28
  • Can you do the copy operation multiple times and compare the results to determine if the outcome is random? – I say Reinstate Monica Oct 20 '17 at 13:12
  • 1
    Also, have you tried to do this with XCOPY? – I say Reinstate Monica Oct 20 '17 at 13:18
  • 1
    If you are having problems with xxcopy, you could use instead the built-in robocopy with the /copyall /efsraw parameters. – harrymc Oct 23 '17 at 16:26

This seems to be the solution, at least in SyncBack (no solution found with xxcopy yet):


|improve this answer|||||

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.