Company: Public Education K-12
Software: VMware vSphere
Hardware: Xserve

[William] - Hi Pete, thanks for reaching out on Twitter and offering to share your experiences in managing VMware and Apple OS X in an academic environment. Can you start off by quickly introducing yourself and what your role is currently?

[Pete] - My name is Pete Wann, I've been a sysadmin for over 15 years, mostly in education. I switched to Mac at the OSX transition because I was really interested in the Unix (BSD) foundation. My interest in Unix was piqued by my exposure to Solaris in the military, and since then I've tried to focus my career around all the various flavors out there, it just so happens that I like Macs, and it's been a good niche to be in. The community is awesome and ridiculously supportive.

My current role is as a Principal Systems Technologist at Oracle. I work for our Global IT group, but I primarily support a subset of our Marketing department. I'm responsible for the infrastructure around our video, print, and web production efforts. Although, the specific implementation we're going to discuss was done at my last position, with a large school district in Alaska.

[William] - Thanks for the background Pete. So I hear you were involved in an implementation that involved VMware and Apple OS X Technologies, can you share with us some more details about the environment?

[Pete] - Well, as you know, Apple discontinued the Xserve in 2010. (boo! hiss!) This was disastrous for that environment since the schools were very far apart, and our WAN links were slow and sometimes tenuous, in addition to some decisions made before I arrived about how home directories were handled, we needed to have some kind of server presence in every school. Since we couldn't count on having someone in each school who was comfortable going into a server closet to reset a system, we really needed Lights-Out-Management on whatever hardware we put out there.

Additionally, this was by far the largest Open Directory deployment that we (or Apple) had ever heard of. We had both computers and users in OD, and with our sometimes rickety WAN, we needed to have OD replicas as close to the clients as we could get, so again, a server presence in every school.

Eventually we migrated all of our user authentication over to AD, but still used OD for some computer management functions (mostly we used JAMF Casper for imaging and package deployment), so we still needed separate OD replicas for each school. (Each school was its own OU within OD so that we could distribute computer management tasks.)

[William] - I too remember the EOL announcement of the Xserve, it definitely had an impact to everyone who relied on that hardware. It sounds like you had a decent Apple Infrastructure, where was all this running? Physical or Virtual?

[Pete] - At the time, ESX did not support the Apple RAID card, so I could not use the internal storage with any of the systems I had available, which was fine with me, since I didn't want any moving parts on the hosts if I could avoid it, to hopefully increase longevity.

So, after much bugging of the powers-that-be, I got three licenses for vSphere for the three Xserves I scrounged from our secondary schools, removed all internal storage, then installed ESXi on a small USB drive on each host. I used the built-in iSCSI support in ESXi to connect to our NetApp storage, and integrated the Xserves with the rest of our vSphere environment, with full support for vMotion and everything. It was really easy, and worked insanely well.

We wound up virtualizing about 20 hosts across the three Xserves, mostly OS X, but also a couple of Linux hosts to act as web front-ends for our Casper environment. I fought hard to make the Xserves full-fledged members of the vSphere deployment, but my counterparts on the Windows side resisted harder. I still think that was a waste of available CPU power, but such is life.

[William] - Wow, this is pretty cool! I think this is the first implementation that I have heard of that leverages external storage w/Apple hardware. Could you share some details about the hardware specs for the Xserve and how you came to this particular configuration?

[Pete] - Well, in the case of the Xserves, we lucked out by having already ordered 77 of the last generation before Apple announced the end-of-production. We were in the process of transitioning from Xserve G5s to Intel in all the schools.

I was at the MacTech conference in LA when word came out that the Xserve was killed (Can you imagine the mood in that room?) and immediately got in touch with my boss to ask for as many more of the last generation we could afford to buy. Initially my intention was to go with Parallels Server, and we did buy it and deploy it at a couple of sites, but let's just say that didn't go well, and I jumped off that path as soon as ESXi 5 was released.

Initially I wanted dual-processor systems with the internal SSD and maxed RAM (I believe 48GB on that model), and since I was still thinking in terms of what Parallels Server supported, I got 3 internal 1Tb drives to use for local storage. Unfortunately, the option of adding the internal SSD as a fourth drive disappeared almost as quickly as it appeared, and we missed the window. I got the rest of what i asked for, though.

Once I discovered that ESXi 5 didn't support the Apple internal RAID controller, I had to find another solution for storage, since I didn't want to run everything, Hypervisor and VM Storage on USB drives. Fortunately for me, our vSphere environment was already configured to connect to our NetApp NAS, so it was trivial to add that storage for the VMs once the Xserves were added as hosts to the vSphere DC.

I also managed to scrounge additional NICs for the Xserves to give the nodes more network capacity for the guest VMs. So I think ultimately we wound up with 6 total 1Gb connections — 1 management, 1 vMotion etc., and 4 on a vSwitch for guest VMs. The three Xserves were segregated into their own vDC to avoid confusion for our management and SysAdmins.

[William] - How did you go about monitoring this infrastructure? Any challenges or gotchas you found while building and managing this environment?

[Pete] - Honestly, no. We used all of the same management tools that we used for our wider vSphere environment, and it all just worked.

At the time, I believe they were implementing some monitoring tools from Symantec, but I left while that was still being implemented. Before that was in place, it was largely a manual process. I stayed as hands-off as possible once I had my environment up and running because I take a "less is more" approach to being a SysAdmin. 🙂

The ONLY gotcha, and it was very easily overcome, was the lack of support in ESXi 5.0 for the Apple internal RAID controller. That turned out to be good for us, as it forced us to use the existing vSphere infrastructure.

As for management, we just had to embrace a new way of deploying VMs, but there again, once I built a template for vSphere, it was trivial to deploy new Mac VMs, which I then configured as needed. If we'd had a larger environment, I would have leveraged tools like Puppet or Casper to auto-configure hosts to our needs.

[William] - In building out this environment, it sounds like you learned quite a bit. Was this something you already had some experienced with or were you learning on the job? If the latter, were there any key resources you leveraged that helped you build and manage such an infrastructure?

[Pete] - I had experience with VMware from my previous job, where I got involved in deploying new VMware nodes to help transition to a virtual datacenter. In truth, it worked so well and was so easy to set up, I didn't really need support except for gathering the specifics of our environment.

There was literally no difference between the setup for generic x86 hardware and Xserve as far as I could see. The only difference was that in addition to all the other guest OSes, we could also run OS X on these hosts.

[William] - Pete, I would like to thank you very much for your time this afternoon and sharing with us your experiences. I think this has been very informative/educational and should help others thinking about building or managing a similar type of environment. Before we finish up, do you have any words of wisdom or advice to others looking to start a similar project and perhaps also working in the academic/education field?

[Pete] - I would say that if you're thinking about it and if you think that virtualizing OS X will help, then go for it. It's actually easier than you probably think. Also, I'd say to remember that as a SysAdmin, managing up is just as important as managing your systems. Keep your eyes open to what's happening in your industry, and try to be prepared for new things and opportunities to save money and improve efficiency. Especially in public K12, budgets are shrinking, but demands (particularly on IT) are increasing. Don't be afraid to speak up if you think you can find a way to save money and provide the same or a better level of service for your students.

If you are interested in sharing your story with the community (can be completely anonymous) on how you use VMware and Mac OS X in Production, you can reach out to me here.


Thanks for the comment!