Got two warnings this morning. The first is about VSS not loading and the second is a file open result of the first which is the active db file for the job. Snapshots are set to ON for this job. The first has happened on each run since being installed a few days ago.
Environment is Windows 10 21H2 IOT (the one still supported). This pc had Duplicati 2.0.1.8 on it before. I’d tried 2.1 when it was first released a year ago, but abandoned it and reverted to the beta which works fine for me. V2.3.0.1 was loaded after a (mostly?) full removal of the prior versions (may have missed ProgramData) while keeping the .json and .sqlite files for the backup job set. It seem to be mostly working, with this one exception and a port 8300 oddity. I know nothing about VSS really, but I found some commands and will paste their output below.
Duplicati logs:
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2026-05-16 04:40:00 -07 - [Warning-Duplicati.Library.Main.Operation.BackupHandler-SnapshotFailed]: Failed to create a snapshot: Failed to load Windows Component VanaraVssBackup: Exception has been thrown by the target of an invocation.
NotImplementedException: Failed to load Windows Component VanaraVssBackup: Exception has been thrown by the target of an invocation.
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2026-05-16 04:40:00 -07 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-FileLocked]: Excluding path due to file locked: C:\Duplicati_DB\HTPC5brW10\AFDUUROXRM-HTPC5brW10_BUofDupDBs.sqlite-shm
IOException: The process cannot access the file because another process has locked a portion of the file. : ‘\?\C:\Duplicati_DB\HTPC5\AFDUUROXRM-HTPC5brW10_BUofDupDBs.sqlite-shm’.
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Windows commands:
Microsoft Windows [Version 10.0.19044.7291]
(c) Microsoft Corporation. All rights reserved.
C:\WINDOWS\system32>vssadmin list shadowstorage
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2013 Microsoft Corp.
Shadow Copy Storage association
For volume: (C:)\?\Volume{00024d99-0000-0000-0000-903e00000000}
Shadow Copy Storage volume: (C:)\?\Volume{00024d99-0000-0000-0000-903e00000000}
Used Shadow Copy Storage space: 4.95 GB (2%)
Allocated Shadow Copy Storage space: 5.25 GB (2%)
Maximum Shadow Copy Storage space: 10.0 GB (4%)
C:\WINDOWS\system32>vssadmin list help
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2013 Microsoft Corp.
Error: Invalid command.
-— Commands Supported ----
Delete Shadows - Delete volume shadow copies
List Providers - List registered volume shadow copy providers
List Shadows - List existing volume shadow copies
List ShadowStorage - List volume shadow copy storage associations
List Volumes - List volumes eligible for shadow copies
List Writers - List subscribed volume shadow copy writers
Resize ShadowStorage - Resize a volume shadow copy storage association
C:\WINDOWS\system32>vssadmin list Providers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) 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
C:\WINDOWS\system32>vssadmin list Writers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2013 Microsoft Corp.
Writer name: ‘Task Scheduler Writer’
Writer Id: {d61d61c8-d73a-4eee-8cdd-f6f9786b7124}
Writer Instance Id: {1bddd48e-5052-49db-9b07-b96f96727e6b}
State: [1] Stable
Last error: No error
Writer name: ‘VSS Metadata Store Writer’
Writer Id: {75dfb225-e2e4-4d39-9ac9-ffaff65ddf06}
Writer Instance Id: {088e7a7d-09a8-4cc6-a609-ad90e75ddc93}
State: [1] Stable
Last error: No error
Writer name: ‘Performance Counters Writer’
Writer Id: {0bada1de-01a9-4625-8278-69e735f39dd2}
Writer Instance Id: {f0086dda-9efc-47c5-8eb6-a944c3d09381}
State: [1] Stable
Last error: No error
Writer name: ‘System Writer’
Writer Id: {e8132975-6f93-4464-a53e-1050253ae220}
Writer Instance Id: {3bd6c43e-e933-4c50-b2b0-bf44fc2cf263}
State: [1] Stable
Last error: No error
Writer name: ‘MSSearch Service Writer’
Writer Id: {cd3f2362-8bef-46c7-9181-d62844cdc0b2}
Writer Instance Id: {9a995f46-88c5-4fd4-9f9e-4ae60910da45}
State: [1] Stable
Last error: No error
Writer name: ‘ASR Writer’
Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4}
Writer Instance Id: {5b4888b7-f9b3-40bd-bce9-f72cf0319bd8}
State: [1] Stable
Last error: No error
Writer name: ‘Registry Writer’
Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485}
Writer Instance Id: {c5577970-df12-47fb-bbc1-2cb35afb4452}
State: [1] Stable
Last error: No error
Writer name: ‘WMI Writer’
Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0}
Writer Instance Id: {b92dbae2-8e4d-4326-9e20-ebd10cd53bdd}
State: [1] Stable
Last error: No error
Writer name: ‘Shadow Copy Optimization Writer’
Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f}
Writer Instance Id: {2ec19b60-1929-441a-b755-4b515279f34d}
State: [1] Stable
Last error: No error
Writer name: ‘COM+ REGDB Writer’
Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f}
Writer Instance Id: {7d376903-607c-4ac7-a640-cb8000205631}
State: [1] Stable
Last error: No error