The problem:

When someone tries to create a shadow on a remote drive the server
refuses to create it.

Advantages:
- Database mirroring (more details on previous threads. Do a search
on the group's webpage at Yahoo! using 'shadow' for full discussions
about this topic. Anyway we can talk again if you want...)

Proposal:

To relax a little bit the constrains imposed by the server in order
to allow us to create a shadow remotely.

I looked a little bit more in detail to the 1.5.3 code base and we
have in parse.cpp

-------8<----------

...
static void define_shadow(void)
...

shadow->fil_name = PARSE_symbol(tok_quoted);
if (!check_filename(shadow->fil_name, FALSE))
PARSE_error(297, 0, 0); /* msg 297: A node name is not
permitted in a shadow or secondary file name */

-------8<----------

If you want, have a look at


static BOOLEAN check_filename( SYM name, USHORT decnet_flag) (located
in parse.cpp)

and, you'll see that it has at the end

return !ISC_check_if_remote(file_name, FALSE);

----------8<----------

Following the code, in isc_file.cpp

we have

BOOLEAN DLL_EXPORT ISC_check_if_remote(TEXT * file_name,
BOOLEAN implicit_flag)
{
/**************************************
*
* I S C _ c h e c k _ i f _ r e m o t e
*
**************************************
*
* Functional description
* Check to see if a path name resolves to a
* remote file. If implicit_flag is TRUE, then
* analyze the path to see if it resolves to a
* file on a remote machine. Otherwise, simply
* check for an explicit node name.
*
**************************************/
...

/* Always check for an explicit TCP node name */

if (ISC_analyze_tcp(temp_name, host_name)) {

return TRUE;
}

...

#if defined(WIN_NT)
/* Check for an explicit named pipe node name */

if (ISC_analyze_pclan(temp_name, host_name)) {

return TRUE;
}

....
}
#endif // WIN_NT

return FALSE;
}

...and if you'll have a look to ISC_analyze_pclan you'll see that it
deals with name pipes, parsing the shares.

----------8<----------

Perhaps someone of you will be so kind to change a bit the
define_shadow from parse.cpp making the 'if' looks like:
if not (check_filename(...) and #ifdefined(WIN_NT)
ISC_analyze_pclan(...) #endif) then <throw parse error>?

(I deliberately wrote in pseudo-code leaving the full choice of
coding solution to you)

What do you think? (from architectural POV)

Any side effects?

(Sorry, I don't know the code very well...)

If someone can build an experimental superserver with this change
please send me an eMail with a link (recommended) or with the kit
attached in order to do some crash tests & benchmarks. (I have some
WinXP/Win2003 machines ready for this. Perhaps that we can put it on
V2.0 - I'll write a small documentation for you about this, how
someone can safeguard his data in this way, if this works, of course)

HTH & TIA,

m. th.

P.S.:

How managed Alex (Peshkov) to create shadows on NFS points... (on
Windows not even with mapped drives I cannot trick the engine...)