Snapshot-policy / VSS not working on Win 10 20H2

Support
#1

Hello!

I’m just starting migrating from old Duplicati to Version 2.
Running Windows 10 20H2 and tried running Duplicati with admin privileges, as service and through Task Scheduler with highest privileges. Nothing changes the following problem.

I have turned smnapshot-policy to “on” but I always get the following message as a warning:

[Warning-Duplicati.Library.Main.Operation.BackupHandler-SnapshotFailed]: Failed to create a snapshot: The provider returned an unexpected error code.

I then tested it with some restricted folders on C: and get many warnings like thise:

[Warning-Duplicati.Library.Main.Operation.Backup.MetadataGenerator.Metadata-MetadataProcessFailed]: Failed to process metadata for “C:\ProgramData\Packages\Microsoft.XboxGamingOverlay_8wekyb3d8bbwe\S-1-5-21-100176517-2775799961-2918127677-1002\SystemAppData\Helium\Cache\8de27c5cbf34241_COM15.dat”, storing empty metadata

I found some threads also having problems with snapshot policies / VSS but so far nothing helped.

Hope you guys have ideas. :slight_smile:

#2

Welcome to the forum @Grau

Please use Event Viewer to see if you can find anything in System log then. That might help understand.

You could also run vssadmin list shadowstorage from a Run as administrator command prompt.

vssadmin list providers might also be helpful.

#3

Hello and thank you! :slight_smile:

I found this under Event Viewer / Windows Logs / Application:

Volume Shadow Copy Service error: Error calling a routine on a Shadow Copy Provider {b5946137-7b9f-4925-af80-51abd60b20d5}. Routine details Cannot ask provider {b5946137-7b9f-4925-af80-51abd60b20d5} if volume is supported. [0x8000ffff] [hr = 0x8000ffff, Catastrophic failure
].

Operation:
Check If Volume Is Supported by Provider

Context:
Execution Context: Coordinator
Provider ID: {00000000-0000-0000-0000-000000000000}
Volume Name: F:\

Here are the responses from the shell commands:

vssadmin list shadowstorage:

vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
© Copyright 2001-2013 Microsoft Corp.

Shadow Copy Storage association
For volume: (C:)\?\Volume{c91070b7-806f-4271-9ed3-5384f6e33dfe}
Shadow Copy Storage volume: (C:)\?\Volume{c91070b7-806f-4271-9ed3-5384f6e33dfe}
Used Shadow Copy Storage space: 2.30 GB (1%)
Allocated Shadow Copy Storage space: 2.67 GB (2%)
Maximum Shadow Copy Storage space: 5.55 GB (4%)

vssadmin list providers

vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
© Copyright 2001-2013 Microsoft Corp.

Provider name: ‘Microsoft Software Shadow Copy provider 1.0’
Provider type: System
Provider Id: {b5946137-7b9f-4925-af80-51abd60b20d5}
Version: 1.0.0.7

If I run the first command for the drives I want to save files from, I get this:

vssadmin list shadowstorage /On=e:
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
© Copyright 2001-2013 Microsoft Corp.

Error: Unexpected failure: Catastrophic failure

Could it be a problem that these drives are encrypted? Wouldn’t still explain the problems from c: which is not encrypted but that’s all the info that comes to my mind right now. :smiley:

#4

Oh well. I just searched for that last part and it seems that VSS is not working from encrypted non-system-drives. :expressionless: