Windows managed to move a file MyDefrag couldn't – how come?

[rstarkov]

I was using the ForcedFill action to free up space at the top of the disk. One of the files was repeatedly marked as unmovable, even after stopping almost all services and processes: C:\System Volume Information\syscache.hve

Fair enough, I thought. I’ll just shrink the volume up to there. At this point I have syscache.hve being the topmost file, then, a couple of gigabytes down, I have a chunk of the pagefile.sys. Nothing else.

So I open Disk Management and ask it to shrink the volume. It goes away and does some magic.

I re-run MyDefrag and what do I find: the volume was shrunk all the way to pagefile.sys! syscache.hve is out of the way! Whatever Windows did to it, MyDefrag couldn’t. Unfortunately I don’t know whether Windows moved it or simply deleted it.

Any chance MyDefrag can be taught to do whatever trick made this possible?

[Darlis]

MyDefrag uses the Windows Defragmentation API to move files but when trying to move syscache.hve it says "access denied".

That mean that MyDefrag does not have the permission to move the file or the Defragmentation API generally refuses to move this file. There is a difference if the file is being moved by a third party program or by Windows itself. Like when shrinking the partition, there are certainly much more internal things going on than just files being moved, to make sure that the system is always in a consistent state. For example, if the MFT is moved you'll notice that your applications will start to hang until the moving has finished because the MFT can't be updated during that time.