What happens if I run out of Google Drive storage?

So I plan to use Duplicati to backup the most important files on my laptop to my free Google Drive (limited to 15 Gb). However, as these already consume ~ 8 Gb, I am worried I might hit the limit at some time. At which size of the source data may problems start to occur, and what would happen if I run out of space on google drive? I set the number of backups to keep to 2. Thanks for your answers in advance.

Welcome to the forum @Fakeacoount12312

That depends on the nature of source data, due to compression and deduplication trying to save space, meaning the 7 GB remaining will probably hold at least 7 GB once, however later changes get uploaded too, and eventually build up. They can be kept under control by deleting old versions, thus freeing space.

The plan to keep only 2 versions (you could probably do more than that, as a version just adds changes) along with automatic compacting will probably keep the size from growing much (unless source grows).

C:\ProgramData\Duplicati\duplicati->Duplicati.CommandLine.exe help quota-warning-threshold
  --quota-warning-threshold (Integer): Threshold for warning about low quota
    Sets a threshold for when to warn about the backend quota being nearly
    exceeded. It is given as a percentage, and a warning is generated if the
    amount of available quota is less than this percentage of the total
    backup size. If the backend does not report the quota information, this
    value will be ignored
    * default value: 10

should start giving you warnings. It’s probably not a great idea to run out completely, as sometimes such messes require manual work to fix. If nothing else, you would have to make some free space manually…

Your job log has a Complete log section that might make it clearer how backups and storage are doing.

"BackendStatistics": {
  "RemoteCalls": 15,
  "BytesUploaded": 6635418,

“TotalQuotaSpace”: 20401094656,
“FreeQuotaSpace”: 8720196216,
“AssignedQuotaSpace”: -1,
“ReportedQuotaError”: false,
“ReportedQuotaWarning”: false,