When provisioning a VDB the "access control lists" (ACLs) of database and log files are modified to help prevent unintentional data loss through file deletion. This could happen if there is an attempt to DROP a VDB directly through SQL Server management studio or other native SQL Server tools.
Each database and log file ACL is updated to include a deny delete "access control entry" (ACE) for the user account running the SQL Server instance.
VDBs can still be dropped directly through SQL Server tools, however a warning message will be displayed and the files will remain on the volume exported by Delphix. This file deletion prevention also applies to attempts to remove files from a database using the ALTER DATABASE .. REMOVE FILE command.
If a VDB is inadvertently dropped, the database can be reattached using SQL Server tools.
If you attempt to delete a database or log file and then try to add a file of the same name this may fail because the original file was prevented from being deleted by the deny delete ACE.
If it is your intention to delete the files from the volume provided by Delphix, the ACLs on the files can be changed using the icacls command.
icacls <file> /remove <SQL Server instance account>:deny(D)
Accounts other than the SQL Server instance account will not be prevented from deleting the VDB database and log files.