Kjell,

> It's a bit strange, because none of the processes on the server has a very
> high value in ANY of the memory related columns in Task Manager.

What does "Peak Working Memory" read for the FB processes?

> So, who's consuming this vast amount of memry? File system cache? How
> can I see?

I suspect that you are running into a known problem with the Win2008 x64 file cache manager -- when you start working with a large database file, the OS wants to keep it all in memory which results is a lot of page writes as the OS tries to free memory for the file cache.

There is an utility "Set_Cache.exe" which is available on the SysInternals site which will allow for the amount of memory used by the file cache to be limited.

Additionally, Win2008R2 SP1 includes a new dynamic memory manager to address some of this problem.

> The fb_inet_server process for the update query has million of I/O reads, of
> course, but the count of page faults stands still.
>
> Perhaps I should increase the page buffer to let FB cache more and do less
> disk I/O? But would that stop the filesystem from using up all the RAM for
> caching? Is this even a problem?

If you are using Classic, reduce your FB cache size to about 500 pages per process at leave the rest to the OS.


Sean