David Szpunar: Lead Engineer, PC Help Services

David's Church Information Technology

September 9th, 2009 at 7:14 pm Print This Post Print This Post

Two Day Nursery Checkin Tech Overhaul

in: Servers

Back in July (I’ve been meaning to write about it since!) I did some maintenance and upgrades on our nursery checkin system. Originally installed on a domain using Windows Server 2000 years ago (although it’s been running on Server 2003 for years), the “server “was and old Dell desktop workstation without even room in the chassis for a second hard drive to run a software RAID mirror. I never got an acceptable configuration through using a domain user and group policy to lock down the system while allowing enough rights to troubleshoot the seven checkin stations (all running Windows XP Pro), and in fact they were all using Local Administer local users, not domain users at all! The system worked, but there were other reasons for some changes.

Near the beginning of the year, I did a P2V (Physical to Virtual) move of the server onto our VMWare infrastructure from the old desktop. Our network, when the checkin system (Parent Pager Plus) was set up seven or eight years ago (before I was hired and was just an occasional volunteer!), wasn’t really reliable from one end of the building (where the server room is) to the other end where the checkin system was located, and thus the “desktop” server placed local to the checkin stations, which were at that time isolated from the rest of the network behind a Linksys cable/DSL router (for security). It worked, mostly, especially when we upgraded to new (but low-end) desktops for the actual checkin stations rather than the first systems we used that were only supposed to support Windows 2000 Professional and had countless hangs, errors, and just weird random stuff happen. The new systems practically ran themselves!

We built a large building addition, including a new lobby, and moved the checkin stations and server a couple of years ago. But none of the hardware changed (we added a few stations and got some (not all) of the stations set up with LCD touchscreen monitors over the years, too). A part of the new building included a new core network including managed HP ProCurve switches with fiber optic connections between the MDF and two IDFs (one of them brand new). The infrastructure could now reliably support moving the server into the server room and into more reliable hardware, so like I said, P2V was the solution! It worked great, except the server was also a Domain Controller for it’s own Active Directory subdomain, and some things didn’t go quite right with the P2V and Active Directory, and replication failed with my main domain controllers. I won’t go into details, but suffice it to say don’t P2V a DC, at least not without knowing what special precautions to take :-) After 60 days of not talking to my other Domain Controllers, the tombstone period was past by the time I looked at it, and I ended up needing to manually remove the entire subdomain from Active Directory, which is beyond the scope of this post. Suffice it to say, I managed to do so, and then I spun up a new virtual machine, running Server 2008, setting it up as a Domain Controller and recreating the subdomain I’d just cleaned up. Before I did this, I went to each checkin station and unjoined it from the old domain, and then re-joined them to the new domain.

Why set up a whole subdomain for checkin stations? Cleanliness and separation/security mainly. It’s not as important now with our current network but I still have the whole system on a separate subnet and VLAN (no Linksys router now :-) and pretty isolated. The clients and the virtual server are the only thing other than the firewall/router that’s on the subnet. And it’s what I did last time, and even though I basically ripped everything out, I was happy with the design decisions still, just not the implementation. So it’s still a subdomain, but with a Server 2008 DC that’s properly replicating to my other DCs.

What else changed? Well, we’re running SQL Express rather than MSDE 2000, for one. Also, Windows XP’s new Client Side Preferences addon was released, adding a ton of easy control via Group Policy! Using the new Preferences, I was able to reduce the user permissions while still allowing things like hidden drive maps to utilities, forcing custom registry entries to be maintained on login for many Parent Pager Plus settings that the checkin systems all shared (so if you log off and back on or reboot, those common settings return to their correct defaults regardless of whether they had been changed). I even customized the screen saver that says “TOUCH HERE TO START” in the Marquee so it is automatically pushed down to each client with the correct text and timeouts! Basically, the environment for each checkin station is very controlled with limited visibility, but there’s enough there to make troubleshooting easy if you know what to look for. I was also able to use the Preferences targeting options to very easily apply different registry settings in some cases to the checkin stations used at the manned desk area vs. the unmanned stations, so Parent Pager Plus defaults to the correct (but different) username at each login, for instance. The flexibility in the Preferences is absolutely amazing, and is the missing piece that I wished I’d had the last time I tried locking the systems down years ago with Group Policies when I failed. All checkin stations are not only joined to the domain but log in to a common domain username instead of local users. Although there are a lot of tweaks in Group Policy, there are only a couple of GPOs and thus policy processing time is short and the computers boot reasonably fast given their age.

I basically spent two (long) days dedicated entirely to this project, on a Monday and Tuesday one week in late July. In those two days, I managed to convert the old subdomain to a new one on a new server with a new database, restored the database from the old server’s backup, upgraded Parent Pager Plus to the newest version (forgot to mention this earlier but it needed to be upgraded so I went ahead and did it while I was working on it already), rejoined all computers to the new domain, set up group policies in excruciating detail and tested extensively. I think the efford was well worth it and the result is a system that feels current and up-to-date even though the hardware is still years old and I spent nothing but time! It feels good to complete a project quickly and successfully. If you have questions about any of the process including Group Policy Preferences, let me know. If I took the time to detail every change I made to do the lockdown, I’d spend a lot more time on this post and ever get it published, but my original intention was to document it all here. That may come later, but if you have specific questions let me know!