Problem with robocopy
brucine Posted messages 24516 Registration date Status Membre Last intervention -
Hello,
I found some unreadable files after "robocopy /B" that are otherwise accessible on the source.
I ran sfc /scannow on both the internal disk (source) and the external disk (destination) without detecting any issues.
I'm requesting a bit of help.
Thanks in advance.
Best regards.
Barou SANOGO
1 réponse
Hello,
The /B parameter taken by itself does not make sense.
It only allows the copying of files for which there are no NTFS permissions.
Copying "unauthorized" files will not make them unreadable; it will simply fail.
We need to clarify what is meant by "unreadable": are they corrupted at the destination, what type of file is it, how are we trying to read them, from the same PC on the destination medium with the same account rights on that medium, or from another PC?
Personally, I have no problem reading a ROBOCOPY /MIR or XXCOPY /CLONE backup, which is essentially the same, on an external drive connected to the PC, but it is true that I only back up data, not system files that may be in use or protected, including because the owner is not the administrator but a "super-administrator" type System or TrustedInstaller.
Thank you for these clarifications. I'm trying to save data. Taken individually (the unreadable ones from the external drive) on a USB stick, the file (xlsx for example) is readable.
The problem is that the folder is too large (350 GB).
I have done: robocopy "c:\source" "d:\destination" /B. All the data is copied, but some of them won’t open (yet they are fine on the source).
350 Go of data?
I partitioned my hard drive so that the data is on a dedicated partition; all I need to do is a couple of lines (XXCOPY in my case) to backup this data plus some odds and ends that remain on the system partition (for instance, the Firefox profile).
So, start by checking if these 350 Go are indeed data, or refine the paths.
If it's an external drive on your own PC, there is no reason for NTFS permissions to come into play unless you are copying the system partition, which seems unnecessary.
To rule out the possibility of corruption related to transferring too much data, I would start by copying the source to the destination using File Explorer.
All I have left to do is schedule an incremental backup in the format:
I've used variables for the source and destination, previously defined in a Batch; if not, I will of course write the fully qualified paths.
The /L switch allows you to "taste" by simulating the copy to see the results, provided you follow it with a pause line to read them; you can remove it once the desired result is achieved.
Also be cautious about paths that might be too long (over 255 characters in memory and should be reduced) or the presence of spaces or special characters, which is never advisable (limit the case by putting the paths in quotes).