Windows network error on large files

[databoxer]

I am trying to sync from my NAS to a USB drive, so that I can keep an offsite copy of my backups from the NAS. The problem is that a bunch of the NAS files are 500GB+ image backups (some are even 1TB+), and Windows seems to have some kind of bug wherein it gets occasional network errors on large file transfers. When that happens, FFS pops up with options: "Ignore", "Ignore All", "Retry" or "Cancel". If I select "Retry", FFS goes back to the beginning of the file, often after having already completed hundreds of gigabytes, so the Retry effectively takes hours. This also happens when I am using "File Contents" for the comparison method, in which case FFS restarts the full file read, again taking hours.

This isn't really the fault of FFS, but it would be nice if there were an option something like "Seek back 1MB and retry from there", which could work either for copying or comparing. Is there a way to do that? [I have searched this forum and haven't found any relevant topics, though it is difficult to know exactly what search terms to use.]

Thanks!

[xCSxXenon]

That is how file transfers work in general unfortunately. You may use something like 7zip to split the large files up into smaller chunks. Then any networks issues will only restart that chunk and not the whole dataset. Or improve the network setup

[therube]

[Aside from the actual issue you have...]

Related, does File Transfer/tool With file chunk hashing exist.

[databoxer]

FWIW, I booted the exact same laptop under Mint Linux and installed FreeFileSync for Linux. The FFS compare and sync ran flawlessly for almost 2 days, with well over 10TB of data. FFS on Windows was never able to run anywhere near that long without a network error, so this is definitely a Windows bug. I don't think that 7zip would run long enough with a network error to even split the file, as was suggested. Frustrating. This bug seems to have been known for a long time, but Microsoft doesn't seem to be addressing it.

Thus, I still think that the "Seek Back 1MB and Retry" would be a very nice FFS feature to help with this bug, so please put that in the feature request queue.

Thanks to all for your help!

[LeoW]

Hi databoxer,

In your case you might want to try running the Linux version of FFS on your Windows computer.
Windows now has WSL 2 which is a full installation of Ubuntu Linux. Windows Subsystem For Linux.

I use both Windows & Linux too. Linux does a better job, I think, with really big files and also directories with several thousand files. There are other Linux apps that I use on Windows to manage large file systems or remote connections with extra large directories.

I just successfully installed and ran FFS for Linux on my Windows 11 machine.
WSL Windows Subsystem for Linux is available in the Microsoft Store.

FFS first complained about a missing dependency. sudo apt install libgtk2.0-0 solved that problem.
Then, you need to correctly export the DISPLAY setting with:
set DISPLAY = 0:0

then, you can run "freefilesync" and the Linux edition of FFS will launch and run normally. You do this from a Ubuntu terminal window.

The Windows C: drive is automatically mounted for you as /mnt/c

You can even install the GUI file manager Nemo if you wish. I run it on all my Windows computers.

Let me know if you need any further details for installation.

FFS installed under WSL2.png (125.63 KiB) Viewed 471 times