Disaster-proof virtualisation on a dime: how I did it
- 21 August, 2009 03:18
Most companies virtualize servers to save money, save space and act faster on IT requests from the business. Human-resources outsourcing service The Sullivan Group virtualized its servers partially because company executives were worried about hurricanes.
"We're in Savannah [Georgia], so we're right on the coast, and we've had a few [hurricanes] miss us by a little and go North to Hilton Head or Charleston, or hit south of us, but our luck's not going to hold forever," says Robert Jones, the company's IT director.
As he spoke recently by phone to a reporter far outside the hurricane zone, thunder crashed in the background as if to demonstrate that late-summer storms on the Georgia coast are no trivial thing.
An Unusual Choice
Neither is setting up and maintaining a bank of Linux servers, especially a bank of Linux servers running a bunch of virtual desktops for employees, a brand-new CRM suite and a series of online job boards for job-seekers in Georgia. These server also had to be braced for the additional traffic that would come from adding Web interfaces so that several thousand customers could get directly to the financial, benefits and management applications that Sullivan runs for them.
This type of Linux choice is not typical of two-person IT staffs, especially those who are in the middle of major upgrades, analysts say.
"I like Linux, I trust Linux," Jones says. "I was familiar with VMware and we had run it on a couple of servers, but it didn't have the HA capabilities we needed when we were doing this [in spring, 2008], so we were more drawn to Citrix," he says. "Right now, all our Microsoft products run on top of Linux, and that's the way it should be."
Much of the drive to upgrade came from the impending rollout of a customized version of Microsoft's Dynamics CRM suite that would handle the payroll, financial management, compliance reporting and other applications that Sullivan uses internally and supports for customers.
Jones didn't want and couldn't afford the packaged VMware virtual infrastructure, however, Instead, the company installed Citrix Systems XenServer with Marathon Technology's everRun VM high-availability functions-which can mirror real and virtual servers to redundant machines to ensure that data isn't lost if the primaries go out.
Microsoft's hypervisor was just coming out and the host of HA/DR applications available for Windows Server didn't fit the bill for a company that didn't want to run a lot of Windows servers, Jones says.
"There were a lot of factors that went into the decision, primarily the software upgrade [to CRM] and that we couldn't pick up 10 physical servers and move them if we had to," according to Erika Simpson, Sullivan's network administrator. "We could load the VMs on an external hard drive and go, though."
Being able to walk out the door with VMs in hand and set up in a rented space, at Sullivan's Atlanta office, or at the office of a company with which Sullivan has an informal space-sharing agreement if either should have to move temporarily following a disaster, gives it the kind of options it could never have afforded a couple of years ago, Jones says.
Low-Cost Disaster Proofing
Currently the company is running on four servers-about 10 VMs on each physical host except the one supporting virtual desktops, which runs 35. There are four or five physical machines left to convert to VMs, but the system is stable under testing for the Web interface Jones and Simpson are working on that will give "a couple of thousand" users at client companies direct access to the applications Sullivan supports.
The project cost between $55,000 and $60,000 for the initial Citrix and Marathon licenses and physical hosts, Jones says. Going up to four servers to support the CRM software and remote desktops, and to support Web access for external users, cost another $30,000 or so, Jones says. The CRM solution cost about $300,000.
Jones would also have liked to install Xen Desktop Server, which supplies the virtual desktop infrastructure that would have made it far more efficient to run 25 or 30 virtual desktops out of the tiny server closet that Sullivan uses as a data center.
The budget wouldn't allow, however, so he's running instances of Windows XP as virtual machines on one of the Xen servers, though he plans to upgrade eventually.
"That would be a sticking point, but virtual desktop migrations almost always come in stages," according to Bob O'Donnell, an analyst specializing in client and display technologies for IDC. "It would be ideal to be able to make the leap to VDI all at once, but the practical realities of finance and maintaining operations while you're migrating often preclude that."
Mixing Multiple Technologies
In fact, though the mix of Linux and Microsoft, non-VDI desktop infrastructure and minimum-cost approach may have led Sullivan Group to some odd technical choices, its situation and decisions seem unusual only because most virtualization projects that are publicized tend to be more homogeneous than normal, according to Chris Wolf, infrastructure analyst at The Burton Group.
"Smaller companies are where VARs like to get creative. Some [small and medium-sized enterprise] customers are using core VMware virtualization, but management from VizionCore or another ISV that caters to SMEs. Some VARs are taking out a package of VMware with DoubleTake, or Windows apps replicated to virtualized environments in a co-location facility," Wolf says. "There's a lot more variety in the real world than you'd think."
Sullivan's approach is almost by the book, in fact, if you look at it as a way for a small company to get high availability without paying high prices to either a traditional HA company or VMware, according to Mark Bowker, infrastructure analyst at the Enterprise Strategy Group.
"Marathon has been working with Citrix for a long time, and they have the ability to control host-based replication and extend that over distances, so that replication could really be the driver for a company to deploy if they're looking for HA," Bowker says. "We already know Windows Server 2003 runs on a lot of VMs, so there's no reason XP or Vista can't do the same thing.
"[Sullivan] doesn't have a VDI infrastructure in place, but even that's not too unusual in that kind of environment," he says.
The reality that there are many products from many vendors that accomplish similar things and can be fit together to accomplish a specific set of goals tends to get lost in most virtualization marketing, Bowker says.
"A lot of my conversations with vendors are about that," he says. "Everyone has their own agenda and the way they have to slice things, and reality shouldn't intrude. There's a lot more going on in most data centers than people think."
Going off the main path just requires a little extra knowledge, or a little extra work, Wolf agrees.
"It wasn't that complicated to do," Simpson says. "We were up in about a week and haven't run into any big problems."
Well, there was the RAID card that failed in one of the new servers a week after the upgrade; but as the server failed, another took over and Jones and Simpson found out about it later.
"We didn't even know it happened until it was done," Jones says.
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