If you are running 64bit od this could maybe help out.
On 64 bit system there is no initial limit on RAM used for file caching.
Problems can occur when you have DB file that is larger or close to your available RAM size.
On operations that require reading of whole db file (such are sweep, backup/restore etc), OS tries to cache whole file and eats up all available ram eventually bringing whole OS to its knees or worse.
If this can be the case, you could:
a) switch to 2.5 where there is parameter to restrict OS file cache size
b) disable filesystem caching on 2.1.3 (recomanded for superserver only)
c) manually set file cache limit using 3rd party software.
You can read this post too:
FileSystemCache on 64bit OS dilemma
Hope this helps
Best regards

--- In firebird-support@yahoogroups.com, "tomsee7" <tomconlon7@...> wrote:
>
> Environment:
> Intel Xeon 2.27GHz
> 6GB Ram
> SBS 2008
> Windows Server Standard FE SP2
>
> FB 2.1.3.18185 32-bit
> Db Pagesize=8192
> Forced Writes=enabled
> only 1 FB DB in use on this server.
> It is not ideal but 2 other RDBMS are running on this server:
> MSSQL (MS EXchange, etc) + Adaptive Server (symantec av)
>
> [firebird.conf]
> DefaultDbCachePages = 8192
> (No other mods to .conf)
>
> Memory peaked at 1.5GB.
> Restarted, steadily over 30mins went up to 800MB then
> suddenly dropped to its norm ~ 200MB.
>
> It's a mystery as to what could cause this so if anyone has any ideas it would be much appreciated. I've not installed FB 64-bit as I've stayed with what has been known - perhaps it should be installed?
> Also should #MaxFileSystemCache = 65536 be uncommented and set to an new value in light of this?
>
> Thanks,
> Tom
>