I recently ran into the following error when trying to install Polybase on SQL Server 2017 Enterprise:
MODIFY FILE failed. Specified size is less than or equal to current size
Polybase creates three new databases during the installation:
The installation seems to have a problem creating these new databases when using the file settings on the model database.
To get around this, toggle over to SQL Server Management Studio and change the file settings on the model database. In my case, they were set to 1024 MB, 512 MB (Logs), and 512 MB autogrowth.
I changed it to 512 MB, 71 MB (Logs, and 10 MB (autogrowth)
I then toggled back to the Polybase installation, clicked Retry and it worked! After the installation, I then went back and changed my model file size settings back to what they were.