Add progress to --export

[KevinHake]

Exporting a distro to a tar file with wsl.exe --export can take a long time, during which there is no feedback to the user. It would be nice to optionally see something like a progress bar, so the user knows the command is not stalled, and can estimate how much more time is needed to complete the task.

[thomasaull]

As a workaround, you can check how big the exported .tar file is and compare it with the size of your vhdx I guess?

[tautomer]

Another workaround is to check the disk usage and network usage (only when the backup is stored on a remote disk).

[b-hayes]

The thing is mine appears like it should be finished with the tar file being 17gig, no disk usage etc but the export has not finished.
How can I reliably tell if it is finished and that the export is safe to re-use on another system? Any kind of feedback would be nice.

[EvidentlyCube]

Another reason to have ANY kind of feedback - my Win 11 broke overnight and I am preparing to reinstall the system and I don't know if the export is happening (in which case I'll wait for it to finish) or if it's just there happily doing nothing.

[agarwalvaibhav0211]

A much needed feature. My vhdx is 20gb, but the tar file shows zero mb size after waiting for 2 hours. When I cancel the command thinking the export is not working, the tar file suddenly becomes 15GB in size. Thus a progress bar would be a good feature

[gsusI]

A much needed feature. My vhdx is 20gb, but the tar file shows zero mb size after waiting for 2 hours. When I cancel the command thinking the export is not working, the tar file suddenly becomes 15GB in size. Thus a progress bar would be a good feature

This is exactly the issue I encountered, the tar file size is not updated until the process is killed or finished.

My WHDX is 75GB, so exporting becomes a painful process.

Also, errors can occur, so a process that doesn't give feedback for hours can become very frustrating.

Using the trick suggested by @tautomer helps as, at least, I can see that the export process is writing something.

[gsusI]

So... in terms of figuring out the size of the exported tar to understand the progress of the export process:

• File explorer shows 0KB
  

• Powershell was showing 0KB, too
  

But, when I ran WinDirStat for that folder... tachan!

Then, the even more interesting part, ls now shows the size

🤷‍♂️

[ezrag26]

As a workaround, you can check how big the exported .tar file is and compare it with the size of your vhdx I guess?

I wasn't able to see it update when refreshing the folder (which usually helps other times) but I was able to see it change after double clicking on the file, in case this helps anyone else.

[jepdavidson]

I know this is an old issue, but in case it helps anyone:

On Windows11, I also see 0 KB reported as the tar file size in Windows explorer. However, I found that right-clicking the file and choosing 'properties' from the context menu will show the file size.

The property window can be closed and the process repeated to monitor progress.

[eburnette]

Why is it so slow anyway? My docker-desktop-data vhdx is 642GB, and it's... taking... forever.... Task manager shows 12% CPU, and the C: drive (SSD) shows 142MB/s reads. I could have copied the vhdx file many times over by now (over an hour). I know there's a regedit workaround, but I'm wary of going that route.

[KevinHake]

Why is it so slow anyway? My docker-desktop-data vhdx is 642GB, and it's... taking... forever.... Task manager shows 12% CPU, and the C: drive (SSD) shows 142MB/s reads.

Well, 642GB at 142MB/s is something like 75 minutes, and presumably you're writing the copy out to the same drive, so add to that the size / write speed (it'll depend on your hardware if/how much reading and writing can happen in parallel). Do you know how long it did take to finish?

For comparison, my big old spinning disk drive does a ~53MB/s copy of sequential data, and my 980 Pro SSD copying a big git repo (lots of randomly sized files) averages ~100MB/s (in native linux)... so an hour 50 minutes is right around what I'd expect on my SSD.

According to this: https://github.com/Microsoft/WSL/blob/master/CONTRIBUTING.md we have some tools available to get logs about what's happening when the command is issued, so that might make the solution (adding a progress bar) obvious (and might also make it more clear it's not stalled). Not sure if anyone with access to the code will see this, considering I opened it 4 years ago, but if someone wanted to post logs maybe it would help (I'm no longer using Windows, so it probably won't be me).