[Samba] Samba performance issues

[John Coston]

Hi all
We are implementing samba-ldap to act as an nt pdc and are seeing 
performance problems.
We have a 1ghz, 3gb Ram, 36gb box that is running samba-2.2.5 and 
openldap-2.0.23 under redhat 7.3 with kernel 2.4.18-3.
Clients are all Win2k SP3.
All the ldap requests are to the localhost interface.
The box is acting as the PDC for the domain, and also sharing diskspace 
and printers.
When we get around 30-40 smbd processes running everything slows to a 
crawl. we have about 30 slapd processes running, and the total process 
count for the box is about 130 at this point.
here is the output of top at this point:
  12:46pm  up 2 days, 17:14,  3 users,  load average: 20.24, 20.26, 20.51
129 processes: 106 sleeping, 23 running, 0 zombie, 0 stopped
CPU states: 36.1% user, 63.8% system,  0.0% nice,  0.0% idle
Mem:  3229040K av, 3166372K used,   62668K free,       0K shrd,  
148480K buff
Swap:  513976K av,       0K used,  513976K free                 
2758060K cached

We would like to support about 100 simultaneous users.
We were using mandatory server based profiles, but have discontinued 
them to try and improve performance.
So, my questions are:

1. Is the amount of processes desired unreasonable for the hardware?

2. If so, does anybody have some figures on users supported for a 
particular hardware configuration?

3. We are seeing (using smbstatus) exclusive oplocks on files that are 
on read-only (both in the share definition and the filesystem 
permissions) shares. Should this be happening? Could we use 
fake_oplocks on the share to improve performance?

4. Has anybody had any luck with mandatory server-based profiles?

any help or suggestions would be greatly appreciated.
John