As far as I understand Firebird version 2.5 should be able:

RemoteFileOpenAbility
Nickolay Samofatov
Tracker entry: CORE-2263

Code from Red Soft was incorporated, to make this extreme option available to Windows and allow a database to be opened on a network share, in line with the long-time ability to allow access to a database on a NFS device on POSIX.

It is offered in the interests of maintaining feature consistency across platforms. There is no associated architectural change or any implication that its use in practice is considered safer now than in the past. However, it makes it possible to shadow databases to mapped locations and to connect to a database on an external filesystem for a specific, well-tested, safe purpose. An example given was a database kept under lock-and-key on a USB device that could be plugged in to a diskless workstation for performing an occasional, isolated security task

--- In firebird-support@yahoogroups.com, "paulfirebird@..." <paul.vanderlinden@...> wrote:
>
> Hi all,
>
> I'm struggling with embedded firebird which has to open (Yes, I know the risks, and to be absolutely sure I created a readonly database with gbak) a database on a ntfs share.
>
> When I call isc_attach_database (via delphi/interbase or visual studio/firebirdsql.data.firebird.dll) I get the 335544721 (Unable to complete network request to host) error.
>
> I tried firebird 1.5, 1.5.2 and the latest (2.1.3) and neither works.
>
> I set the RemoteFileOpenAbility = 1 in the firebird.conf, I checked with procmon that the gds32.dll is loaded, and that the firebird.conf is read.
>
> What else can I do to get this going?
>
> Os:Win xp sp2
>