Ciao, Duilio,

I was hoping someone with more experience than I would answer your
question, since I've never experienced corruption of an InterBase
database (which seems to have happened to you), except for one time
when I was playing with some command-line tools to see what they did
:-) -- it was, of course, a test database.

On Thursday 2002-02-07 at 09:36:45 +0100, Duilio Foschi wrote:

> a few days ago I installed FB on a PC running W2000 professional, v.
> 5.00.2195.
>
> Today I tried a backup for the first time.
>
> >From the command prompt, I wrote:
>
> \programs\firebird\gbak -b -user SYSDBA -pas masterkey foo.gdb foo.bk
>
> I get the following error messages:
>
> "message length error (encountered 244 expected 246)"
>
> "gds_$ received failed"
>
> "exiting before completion due to errors"
>
> "cannot disconnect database with open transactions (1 active)"


It seems that you've managed to corrupt your database somehow. The
question is, how? Some possibilities come to mind:

1. You were playing around with command line tools ;-)

2. The W2000 machine crashed, and you didn't have "forced writes" turned
on (though this is unlikely, since I believe FB now turns it on by
default on Windows platforms because of Windows' apparently broken
lazy writes).

3. You were using IBConsole or some other admin tool known to be
seriously buggy (I've used IBConsole in the past with no problem, but
others haven't been so lucky -- I suppose it depended on which version
one was using and what one was doing with it). [By the way, I
haven't used IBConsole for quite a while now, so who knows, it may
have substantially improved since then.]

4. You were using different connect strings from Windows client
machines.

5. You were mixing remote and local access to the same database (I'm
pretty sure that's a no-no, from what I've read, but I've never tried
it myself ;-))


Perhaps others can add to this list, but I suspect other conditions
that may corrupt an InterBase database aren't so likely to occur.



>
> What does it mean ?

Hopefully, it means you were using a test database that can be
re-created from a script... :-)



>
> What is causing problems ?
>
> In particular, all users were disconnected at the time, so I cannot
> understand how a transaction could be open...

Perhaps the part of the database that keeps track of trasactions was
corrupted.


Maybe we need a list of the "Top Ten Things Not To Do With
InterBase/Firebird In Order To Stay Sane"

Ciao,

David Trudgett