>In truth, I hate to say what I've done in the end is replace our Samba server with a Win2k8 box, and have the Linux boxes mount its storage over CIFS. All these pain points just go away, to the point where I think Windows is currently a much better file server for Linux boxes than Linux its self is at least for some workloads. For one thing, I have volume shadow copy snapshots now, which are so massively better than LVM snapshots that it's hard to believe.
Unless you have a powerful technical or ideological objection, I would seriously recommend taking a good, hard look at Solaris.
I've only been trialling Openindiana for a couple of weeks, so it's certainly possible that there are major headaches to come, but so far it has been an incomparably better experience than using Linux + Samba - so much so that I deeply regret wasting my life on the latter for so long.