At 04:29 PM 30/08/2007, you wrote:

>Here's some more information on the setup:
>
>The Firebird-version is LI-V1.5.0.4290 Firebird 1.5
>
>It's running on quite an old Linux-server with Kernel version 2.4.20
>(smp) on a
>Red Hat Linux 9 (Shrike).
>I'm planning to upgrade the server to an ubuntu or debian installation
>soon, though...
>
>There are no related messages in firebird.log, the last message is
>three days old
>and TCP/IP-related (receive in try_connect errno = 104).
>
>The system is being used by approx. 10-17 users, with only a few databases
>(one productive, a few for development) of small size (< 2GB).
>
>If you need any other info, please let me know.

Is it possible that someone rebooted the server, possibly for the
first time since you started running Fb 1.5?

Superserver? If so, I think it's highly possible you have
encountered a situation that is peculiarly a quirk of running
Firebird on Red Hat 9 and it's so long since anyone had to think
about the workaround that it has been forgotten. Please download the
1.5.4 releasenotes and read page 88, where it begins:

NTPL problems on higher Linuxen

The new NPTL (Native POSIX Thread Library) in Red Hat 9 (so far) will
cause problems for SuperServer and locally compiled programs....

./heLen