LiteSpeed fails to restore from or backup to mapped network drives. The most common failure cause is incorrect access permissions to the share or the underlying folder(s). Access to the share can be tested by logging into the console of the SQL Server as the SQL Service account.
This is the same functionality limitation that is seen in SQL Server. LiteSpeed uses the Microsoft VDI (Virtual Device Interface) to connect to SQL Server, so this is expected behavior.
Microsoft Books Online: http://support.microsoft.com/kb/555128/en-us
Use the full UNC path, as opposed to the mapped drive. Mapped drives are not supported by Microsoft SQL Server.
Example: Instead of using something like N:\ , change the path to \\Servername\Sharename.
This path can be verified by logging onto the server where the folder is located and finding it using File | Run. Copy the correct path by double-checking it in WIndows Explorer. Copy that successful path back to LiteSpeed.
Provided the network resource is shared and can be accessed. Backups to a network folder require the following prerequisites:
1) The SQL Server service must be running under a domain-level account.
2) The SQL Server service account must have FULL CONTROL rights to the file system folder and to the share.
3) The remote share should only be accessed via UNC name. Mapped drives may not be consistently visible to the SQL Service.