Whan I asked my server:

tbase6.1 P 5
he answered;
Busy: 4 ReadIn:1996 Free:0 Upd.:4 (Tot.: 2000 Waterm.: 1250)

Can someone explain me (in detail) what buffers parameter mean?
What does it mean when busy is only 4 and Free is 0
(and what Watermark helps?);
What is the job of busy/readin/free/upd buffers

Technical manual doesn't give me clear answers.

Thanks

In your example you have 2000 buffer assigned within shared memory for buffer cache.
Readin - 1996 so those are filled, 4 busy means modified buffers and 0 free makes sense since all 2000 buffers are in used.

If <watermark> number of buffers are dirty (modified) then bisam will start flushing them to disk. Independent of that they will be flushed by the timer (normally every 60 seconds).

Regards,
Han

Does it mean that I have to change values and make it higher?
Do I have to have free buffers?
What is good values for 35 concurent BW users?
How to see how often flusher have to flush to disk?

Thanks in advance