Output of restic version

restic 0.11.0 compiled with go1.15.3 on windows/amd64

How did you run restic exactly?

.\restic.exe backup --use-fs-snapshot --cache-dir \\fileserver\shared\.cache --exclude-caches -r rest:http://[...] --exclude C:\swapfile.sys --exclude C:\hiberfil.sys --exclude C:\pagefile.sys C:\

My local machine is running Windows 20H2. I encountered the problem while backing up a 1 TB HDD and again when I swapped that for a 1 TB SSD (thinking that the slow HDD was to blame).

What backend/server/service did you use to store the repository?

I'm using a REST backend on a remote machine.

Expected behavior

Restic should successfully make a filesystem snapshot before running normally.

Actual behavior

repository 94fe90ee opened successfully, password is correct
creating VSS snapshot for [c:\]
error: failed to create snapshot for [c:\]: VSS error: async operation pending

Restic continues working after that error (should it be fatal?) and backs up all files that it can access, but obviously those in use are inaccessible because it doesn't believe it has a working shadow copy. However, the shadow copy was created by the OS and is available during restic's run.

Steps to reproduce the behavior

I was able to reproduce this by running the backup command again, whether or not I first cleared out all shadow copies. I've rebooted several times since and can no longer reproduce the problem.

Do you have any idea what may have caused this?

No clue! It seems like there might be some timeout or race condition waiting for VSS to create the shadow copy.

Do you have an idea how to solve the issue?

Unfortunately not.

Did restic help you today? Did it make you happy in any way?

I love restic and use it to back up about 15TB on a regular basis. I'm a huge fan of its deduplication.