Monday, February 18, 2008

Active Directory and DeltaV

Well, a belated Happy New Year (and Valentine’s Day). But let me be the first to wish everyone a happy President’s Day.

So here’s one to watch out for – I don’t know how often this happens to DeltaV systems in the real world, but it has happened twice to us in our shop within the last year, so I thought I’d mention it. Apparently, among the many “oh, by the way” issues with Windows, there’s a flaw in Active Directory that causes a user account to be corrupted. I’m told on really large Active Directories (10,000 plus users), this can happen daily.

Well, imagine your not so large DeltaV system, setup as a domain. The laws of average would imply it could happen here too. But when it happens to the DeltaVAdmin account, look out! Things just sort of stop working, and on a reboot of the ProPlus, you’ve got problems. All those services and DCOM’s that use the DeltaVAdmin account to launch under don’t launch. The permanent fix is to uninstall DeltaV, delete the DeltaVAdmin account, and reinstall DeltaV. Kind of painful, especially in a development environment.

A really clever short term fix is to go into each one of those services and DCOM’s and change their launching account to Administrator. You’ll end up changing 20 or 30 settings (and get really tired of typing your Administrator password), but you’ll keep from having to reinstall DeltaV until you’re ready to do it – which needs to be very soon!