# Duplicati v2.4.0.100_canary_2026-09-04

- Product: Duplicati (https://whatsnew.fyi/product/duplicati)
- Vendor: Duplicati
- Date: 2026-09-04
- Version: v2.4.0.100_canary_2026-09-04
- Original notes: https://github.com/duplicati/duplicati/releases/tag/v2.4.0.100_canary_2026-09-04
- Permalink: https://whatsnew.fyi/product/duplicati/releases/v2.4.0.100-canary-2026-09-04
- Labels: Pre-release

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **added** — Add a new native VSS snapshot provider on Windows that replaces previous providers and does not require VCRedist
- **added** — Add a new WMI VSS snapshot provider to replace the previously supported WMIC provider
- **added** — Enable VSS snapshots for full-disk backups with automatic detection and transparent usage
- **added** — Add support for recreating a database from an interrupted first backup
- **added** — Add `--vss-writer-flush-timeout` option to control how long to wait for VSS writers
- **added** — Add an API endpoint for purging files across backup versions
- **added** — Add permission checks for MS365 and Google Workspace to verify granted permissions
- **added** — Add support for a path prefix in Azure Blob Storage destinations
- **added** — Add sleep prevention support on Linux during backup operations
- **added** — Add `.zsync` file and metadata support for AppImage efficient updates
- **changed** — Change repair handler to report defective metadata instead of silently reassigning it
- **changed** — Change repair handler to direct users to run `list-broken-files` and `purge-broken-files` for metadata issues
- **changed** — Improve detection and notification of zero-length and defective blocksets
- **changed** — Speed up `purge-broken-files` by reusing the invalid-blocks query
- **changed** — Apply performance fixes to local database queries affecting most operations
- **changed** — Automatically exclude `System Volume Information` folder from backups
- **fixed** — Fix Hyper-V and MSSQL enumeration with the native VSS provider
- **fixed** — Fix clean install potentially starting with an empty machine ID
- **deprecated** — Mark `--synchronous-upload` option as deprecated in favor of `--asynchronous-upload-limit`
- **removed** — Remove support for WMIC provider as Windows updates will remove the executable it relies on

This release is a canary release intended to be used for testing.

#### New Native VSS snapshot provider

This release introduces a new native VSS snapshot provider on Windows that replaces the previous providers. Hyper-V and MSSQL enumeration work with the native provider which is now default.

The new native VSS snapshot provider does not require VCRedist to be installed and works on x86, x64, and Arm64 systems.
The existing AlphaVSS and Vanara-based VSS snapshot providers can still be selected (but not on Arm64).
They will be removed in a future version as AlphaVSS is no longer maintained and the new native library has fewer dependencies than Vanara.

#### New WMI VSS snapshot provider

The previously supported WMIC provider has been removed as Windows updates will remove the executable it relies on.
Instead a new WMI snapshot provider is added which works similar to WMIC.

The WMI (and WMIC) provider gives a more light-weight VSS functionality, where it does not flush the writers (MSSQL, HyperV, etc) but just ensures a crash-consistent disk snapshot.

If you rely on systems that integrate with VSS, use the Native provider, if you just want to back up locked files, use the WMI provider.

#### Full-disk backup and VSS snapshots

With this release VSS is now also used for full-disk backups. This is fully transparent and works such that an active snapshot is detected and the full-disk reader will use the snapshot to access the disk contents.

#### Recovering from an interrupted first backup

Interrupting a first backup previously left the destination in an unrecoverable state: blocks and index files were uploaded, but no filelist was written, so neither backup nor repair could proceed. The recreate logic can now reconstruct a database from the index files alone, so an interrupted first backup can be resumed instead of requiring the destination to be discarded, thanks @JamBalaya56562.

#### Repair no longer removes metadata

The repair handler previously attempted to fix defective metadata with various reassignment strategies that could silently remove metadata. It now reports the problem and asks the user to run `list-broken-files` and `purge-broken-files`, which rewire the metadata while keeping the file content. Detection of zero-length and otherwise defective blocksets has also been improved.

#### Azure Blob Storage path support

The Azure Blob Storage backend previously ignored the path part of the destination URL and always stored data in the root of the container. The path is now treated as a prefix, so backups can be placed in a subfolder of a container. If you previously used a path in an Azure Blob Storage destination URL, the data was stored in the root; after upgrading, new backups will use the path as a prefix and will not see the previously uploaded files.

#### Prevent empty machine ID

A startup sequence issue could cause a clean install to report and connect to the console without a machine ID, which could cause various unwanted behaviors.

#### Linux sleep prevention

Duplicati can now prevent the system from sleeping during backup operations on Linux, similar to the existing support on Windows and macOS.

#### AppImage `.zsync` support

This release now has the `.zsync` file and relevant metadata such that future updates can be done efficiently and automatically by AppImage managers that support it.

#### `--synchronous-upload` deprecated

The `--synchronous-upload` option no longer has any effect and is now marked as deprecated. Existing configurations that set it will continue to load, but a warning is now logged. Use `--asynchronous-upload-limit` instead.

#### Default exclude volume information

The `System Volume Information` folder is now automatically excluded from backups as it cannot be reliably read and cannot be used in a restore process.

#### Performance and stability updates

Several performance fixes are applied to the local database queries, affecting most operations, mostly by @JamBalaya5656

_[Truncated at 4000 characters — full notes: https://github.com/duplicati/duplicati/releases/tag/v2.4.0.100_canary_2026-09-04]_