Here's something that Paul Blackman sent me that may be useful:

-------------------
I created this script to do a few things that smbstatus doesn't at the
moment.  Perhaps you might want to include these.  Sorry I haven't
added things at source level, script was quick&easy.

*******
#!/bin/csh
if ($1 == "-p") then
  smbstatus -p |sort -u
else if ($1 == "-c") then
  echo There are `smbstatus -p |sort -u |grep -n -v z |grep -c :` unique smbd processes running.
 else if ($1 == "-l") then
  echo `date '+ %d/%m/%y %H:%M:%S'` `smbstatus -p |sort -u |grep -n -v z |grep -c :` >>$2
else if ($1 == "-cs") then
  echo There are `smbstatus |awk '$1==share {n++;} END {print n}' share=$2` concurrent connections to share: $2
else if ($1 == "-csl") then
 echo `date '+ %d/%m/%y %H:%M:%S'` `smbstatus |awk '$1==share {n++;} END {print n}' share=$2` >>$3
else
 echo "'smbstat -c'         ==> Count unique smbd processes."
 echo "'smbstat -p'         ==> List unique smbd processes."
 echo "'smbstat -l logfile' ==> Append a log entry for the number of"
 echo "                          concurrent and unique processes to logfile."
 echo "'smbstat -cs sharename'"
 echo "                     ==> Count processes connected to sharename (assumed unique)"
 echo "'smbstat -csl sharename logfile'"
 echo "                     ==> Append a log entry for the number of concurrent"
 echo "                         processes connected to sharename (assumed unique)"
endif
******

Run this script from cron eg.

0,5,10,15,20,25,30,35,40,50,55 * * * * /usr/local/samba/bin/smbstat -l /usr/local/samba/var/smbdcount.log

and you get a good idea of usage over time.

Cheers,
~^ MIME OK ^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~
    o        |  Paul Blackman                  ictinus@lake.canberra.edu.au
        o    |  Co-operative Research              ------------------------
   o  _      |  Centre For Freshwater Ecology.        Ph.  (Aus) 06 2012518
  -- (") o   |  University of Canberra, Australia.       Fax. "  06 2015038
    \_|_--   |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |      |  "Spend a little love and get high"
    _/ \_    |                                              - Lenny Kravitz
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~ SAMBA Web Pages: http://samba.anu.edu.au/samba/ ~~~~~~~~~~~~~~