Bug: file copies freeze when symbolic links or junctions are included

Question

It's taken me a while to figure out what was going wrong, but I think I've got it.

I have been reorganizing my filesystems, and the "copy" function has locked up on me a LOT.  CPU use spikes, but task manager says it's all in the "idle" process.  "Cancel" and "pause" have no impact, except that the descriptive text changes.  Eventually, I have to reboot the computer.

I haven't been able to *prove* that it's copying links that has a problem, but if I don't copy links the copy goes fine, but when I do copy links (at least these particular links), the copy locks up.

When I tried to test the behavior, I *did* notice a *drastic* slow-down in copying just a few files; so it may be that it's not actually locking up, just that copying a large number of files "below" a link takes a drastically long time to "calculate" - more than a day for less than 10GB of data.

Here is how I ran the test that failed, but did take longer to copy than expected:

* brand new windows 8 vm (virtualbox), all updates applied and less than ten extra programs installed.

* in an elevated command prompt:

CD \

mkdir temp

cd temp

mkdir test

mklink /d t test

Then in windows explorer, I copied "C:\Temp" to "C:\Temp - copy" by drag-and-drop.  The copy worked just fine.

I deleted "C:\Temp - copy" and "C:\Temp\t" then went back to the elevated command prompt and:

cd \temp

mklink /j t test

Again, windows explorer copied just fine.   I deleted "C:\Temp - copy" but left "C:\Temp\t"

So, using drag-and-drop, I copied all of the files from my "downloads" folder to "C:\Temp\t"

This time when I copied (in Explorer using drag-and-drop) "C:\Temp" to "C:" (creating "C:\Temp - copy"), the copy process to ten times (maybe more, maybe less...I didn't fire up a stopwatch) as long as it did to copy all of my files from downloads to "C:\Temp\T".

That is copying *one* link with 9 files - the big problem shows up if I'm copying more than one link, multiple sub-folders under the link and even links in sub-folders.

(I am using my linked folders to keep web site libraries in one place instead of maintaining multiple versions; I download my javascript libraries like jQuery and knockout to a common "libraries" folder, then create links to the libraries sub-folders for each web site).

Please contact me if you have any questions!

Answer 1

I'm not sure about the steps in the body of this post, but in regards to the title I can verify this happens. I have been doing quite a bit of system wide copying trying to recover things and reinstall Windows. Every time a link is encountered Explorer copy stalls. This happens even on fresh installs of Windows. I thought this was a very consistent bug but I have just copied a folder that included links and it actually worked. So it might be more intermittent than I thought, which is maybe why there aren't many solutions posted online.

At any rate, my solution in the first place is to delete all symbolic links and junctions. Out of the box, most of them are under \Users somewhere, but there are a couple others. I can say from my experience that there are absolutely no detrimental effects from doing this, at least as far as the links created by Window install. I do this mostly to clean up my folder system a bit, but it also helps prevent the Explorer copy bug. As far as the ones created by installing other software, I haven't tried deleting those so I can't say whether that is as safe. You can find all links by opening a command prompt and changing directory to C:\ then type "dir /a:l /s".

The other thing I do is use the program FastCopy, which has no problem with links. I was a bit skeptical of this program at first because of the obvious Japanese translation and use of an uncommon font for the interface that made it look a bit shoddy. But I have tried as many third part copy programs as I could find and this was the best of them. It's lightweight and portable and always works the way you expect.

Answer 2

Hi Earl,

The issue that you are facing is more complex than what is typically answered in the Microsoft Answers forums. It is better suited for the IT Pro audience on TechNet.

Please post your question in the Technet Forum.

You can follow this link to post your question:

http://social.technet.microsoft.com/Forums/windows/en-US/home?forum=w8itproinstallhttp://social.technet.microsoft.com/Forums/windows/en-US/home?category=w8itpro

Thank you. If you have any other queries with Windows, we will be happy to help you further.