Backup to external drive, says success, but source is 0

backing up to external drive, but noticed as it shows success that there are only 1kb files on the destination drive. source is saying 0. Thoughts?
The destination drive is removed occasionally, but typically there prior to backup.

Duplicati: Duplicati.GUI.TrayIcon, Version=, Culture=neutral, PublicKeyToken=null (Duplicati.Library.Main, Version=, Culture=neutral, PublicKeyToken=null)
Autoupdate urls:;
Update folder: C:\ProgramData\Duplicati\updates
Base install folder: C:\Program Files\Duplicati 2
Version name: “” (
Current Version folder C:\Program Files\Duplicati 2
OS: Microsoft Windows NT 6.2.9200.0
64bit: True (True)
Processors: 8
.Net Version: 4.0.30319.42000
Mono: False (0.0) ()
Locale: en-US, en-US, en-US
SQLite: 3.19.3 - System.Data.SQLite.SQLiteConnection
SQLite assembly: C:\Program Files\Duplicati 2\SQLite\win64\System.Data.SQLite.dll

What happens when you do a list files? Or browse and attempt a restore?

Hello @wegunterjr, welcome to the forum!

Is it possible you have filters in place that are excluding everything from your backup?

If you use the “Show log” link of the job menu and click on the most recent row that says “Result” it should expand and show you details of the job run including things like counts and sizes of processed files.

Here’s part of a recent one from one of my machines where you can see that nothing had changed since the last backup of my 12,369 files (taking 3G of space).

DeletedFiles: 0
DeletedFolders: 0
ModifiedFiles: 0
ExaminedFiles: 12369
OpenedFiles: 0
AddedFiles: 0
SizeOfModifiedFiles: 0
SizeOfAddedFiles: 0
SizeOfExaminedFiles: 3229261270

A little further down is a “BackendStatistics” section that includes info about what Duplicati sees at the destination such as the following (I’ve put arrows next to ones you might want to check regarding your destination):

RemoteCalls: 5
BytesUploaded: 0 <~~~~~~~~~~~~~~~~~~~~~~~~~
BytesDownloaded: 52761367
FilesUploaded: 0 <~~~~~~~~~~~~~~~~~~~~~~~~~
FilesDownloaded: 3
FilesDeleted: 0
FoldersCreated: 0 <~~~~~~~~~~~~~~~~~~~~~~~~~
RetryAttempts: 0
UnknownFileSize: 0
UnknownFileCount: 0
KnownFileCount: 215 <~~~~~~~~~~~~~~~~~~~~~~~~~
KnownFileSize: 2918858491 <~~~~~~~~~~~~~~~~~~~~~~~~~
LastBackupDate: 5/16/2018 3:22:00 AM (1526458920)
        RemoteCalls: 7
        BytesUploaded: 1866
        BytesDownloaded: 67021671
        FilesUploaded: 2
        FilesDownloaded: 3
        FilesDeleted: 0
        FoldersCreated: 0
        RetryAttempts: 0
        UnknownFileSize: 0
        UnknownFileCount: 0
        KnownFileCount: 15583
        KnownFileSize: 408063002435
        LastBackupDate: 5/3/2018 1:36:30 PM (1525376190)
        BackupListCount: 3
        TotalQuotaSpace: 4000650883072
        FreeQuotaSpace: 3088465391616
        AssignedQuotaSpace: -1
        ReportedQuotaError: False
        ReportedQuotaWarning: False
        ParsedResult: Success
DeleteResults: null
RepairResults: null
    MainOperation: Test
    Verifications: [
        Value: [],
        Value: [],
        Value: []
    ParsedResult: Success
    EndTime: 5/16/2018 12:32:34 PM (1526495554)
    BeginTime: 5/16/2018 12:32:33 PM (1526495553)
    Duration: 00:00:00.6582511
ParsedResult: Warning
EndTime: 5/16/2018 12:32:34 PM (1526495554)
BeginTime: 5/16/2018 12:32:16 PM (1526495536)
Duration: 00:00:18.0596683
Messages: [
    Compacting not required
Warnings: [
    Failed to create a snapshot: System.UnauthorizedAccessException: Attempted to perform an unauthorized operation.
   at Alphaleonis.Win32.Vss.VssBackupComponents..ctor()
   at Alphaleonis.Win32.Vss.VssImplementation.CreateVssBackupComponents()
   at Duplicati.Library.Snapshots.WindowsSnapshot..ctor(String[] sourcepaths, Dictionary`2 options)
   at Duplicati.Library.Snapshots.SnapshotUtility.CreateWindowsSnapshot(String[] folders, Dictionary`2 options)
   at Duplicati.Library.Main.Operation.BackupHandler.GetSnapshot(String[] sources, Options options, ILogWriter log) => Attempted to perform an unauthorized operation.

So the log for that backup indicates 2 files (totaling only 1,866 bytes) uploaded to the destination. I’m not sure why it would be doing that.

However it looks like at the destination there are 15,583 files (totaling 380G) so there should be quite a few files on your USB drive of at least 24MB.

If you look at your job “Show logs” page and click on the “Remote” button, do you see any put lines between around 05/16/2018 12:32 PM? I expect you should see 2 that, if expanding, should let us know what two files were being uploaded. I suspect at least one might be duplicati-verification.json (usually small, but not that small).

I (possibly incorrectly) recall a recent post involving @kenkendk about small / empty destination files but I can’t seem to find it. Perhaps he or @Pectojin has a thought on why such small files would be created.

Yes, here they are:

May 16, 2018 12:32 PM: put
May 16, 2018 12:32 PM: put

Perfect, thanks!

While it’s possible for the “tail” of a backup to result in a small dblock file (and small related dindex file) it’s not very likely…

I don’t suppose you’re using the --upload-unchanged-backups parameter, are you?

If no files have changed, Duplicati will not upload a backup set. If the backup data is used to verify that a backup was executed, this option will make Duplicati upload a backupset even if it is empty
Default value: “false”

Well, the overflow could easily be that extra block, but it shouldn’t create two small files in the same run since it could just merge them before uploading.

Is it two dblock files? If it’s dindex files then it’s fine since they can be pretty much any size, although usually pretty small.

Only 2 files were updated - a dblock and a dindex with no mention of a dlist (both under 1k). :thinking:

My best guess is that “something” changes between the backups. Usually this would be metadata, like the folder timestamp changing. That would generate some very small volumes, which would then be uploaded.

You can use the affected command to see which files/folders a dblock file holds data for.
To avoid downloading the old volumes, Duplicati will create new small files. After some time, it will consider that there are too many small files and kick in a “compact” step that will download all the small files and produce a single larger file.