System: AIX 5.2 ML-07, Samba 3.0.21a & 3.0.21b, Workstations: Win XP Pro SP2. (OpenLDAP 2.3.11, BDB 4.3) Users are in LDAP pdb. Stand alone DC, no winbindd. This system was upgraded from 3.0.20 to 3.0.21a (and later 3.0.21b). I'm looking for a scenario where under heavy load there could be locking contention within Samba Under heavy load, context switches go through the roof and we get hardly any work done. Trussing shows a lot of locks against what appear to be tdb files. (I'm still narrowing down which ones). Now this could be an AIX problem, ML-08 was just released, but stopping smbd and restarting clears the problem for awhile (read the next day). I'm recompiling 3.0.20b and 3.0.20 to see if the problem goes away. This system is production and never showed any symptoms like this in development. The other thing is all the WS's hitting this server are SP2. We have another server with *exact* same setup and XP boxes with only SP1 hitting it and not quite the same degree of load - no problems. I'm hoping this blurb will shake loose any thoughts on changes since 3.0.20 since a log level 10 is practically impossible with the number of machines hitting it at once. I do have a PMR open with IBM and so far they've only suggested APARs for GPFS (which we're not using). Cheers, Bill