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While virtualization is a common concept, few understand what makes it tick. I'm a firm believer of learning by doing; and in an industry that constantly evolves, we are never short of topics to dig into. A home lab, therefore, can be the cornerstone of personnel development, as it enables you to understand a variety of network and security topics. And one of easiest ways to build a lab is to exploit virtualization so that you can use space-efficient (and more affordable) devices.
Take a walk on the HCL side
Even virtual labs need hardware, and the first step is to find some. There are platforms to suit all budgets, office spaces and performance demands. VMware provides a hardware compatibility list (HCL) detailing servers and components supported in production environments. However, a home VMware lab setup on a budget can be constructed if you wander a little from HCL's beaten path. Here are some to consider:
NUC and Brix -- Next Unit of Computing and Brix manufacture attractive devices for a VMware lab setup at home; they are small, quiet and power efficient. Each packs modern laptop innards into a digital linear tape-sized space. The Intel-anchored NUC is well supported and available in Celeron, Pentium and Core i3, i5, and i7 specifications. With the addition of a switch, you can build a small data center in a briefcase.
The Gigabyte Brix could be considered a clone of the NUC. Sporting similar Intel processors options as the NUC, the Brix uses merchant network cards, SATA and USB controllers. As a result, compared to the equivalent NUC, a few dollars are shaved from the bill. The Brix is less supported, but with some hard work, a satisfactory ESXi host can be built. Asus, Acer and other OEMs produce netops based upon Intel and AMD CPUs, but in these cases, driver support varies widely.
The extreme compactness of these platforms is also an Achilles' heel. Limited by small outline dual in-line memory module specifications and chip capacity, almost all netops have rigid RAM limits of 8 GB to 16 GB. Furthermore, off-the-shelf netops tend to only come with a single Gigabit Ethernet network interface card (NIC). This is fine for limited lab work, but getting the ideal number of interfaces (three) into such a tiny platform typically involves case cutting and/or using USB NICs. A handful of OEMs offer NUC-based devices with additional network cards, but as short-run devices, the bill of material value creeps up.
HPE Microservers -- Hewlett Packard Enterprise's ProLiant Microserver is possibly the best-known home server. There are at least four generations tucked under the desks of network nerds across the world. Although it has never been a powerhouse, a lot of useful equipment is packed in a small(ish) space. The squat Microservers contain four SATA bays, PCI-E slots and integrated lights-out features. The earlier AMD generations are eminently hackable. With silent power supplies, storage upgrades and "less than official" BIOS modifications, these 12-inch cubes have been elevated into little powerhouses.
The price alone has been a selling point; even with a low retail, heavy discounts and rebates are often offered. As a result, many tricked-out Microservers are available on the secondary market. Even the current G8 Pentium-class devices have been offered for as low as $150 after rebates (I know this, as I've just purchased my third). With room for lots of storage, a decent amount of RAM and multiple NICs, the HPE Microservers are only limited by relatively puny standard CPUs. However, if you are handy with a tube of thermal paste, even these can be swapped out for more powerful replacements.
Old laptops -- An old laptop is also a good place to start to build your VMware lab setup. Even an old Intel core-2 Duo processor will probably have virtualization support for 64-bit guests, although it might take a BIOS update to make it work.
Intel provides detailed resources about its CPU processors. This is a valuable tool when spec'ing out your new lab. Another option is to look for secondhand mobile workstations (giant laptops) such as the Dell Precision or older Alienware models. Multiple drive bays, higher-capacity RAM and powerful CPUs can be found in a relatively small form factor, if you can put up with the active cooling.
However, laptops suffer from limitations with NICs and the cost and quantity of RAM. In addition, laptops tend to be worked hard and, thus, may have a finite life expectancy, but upcycling that old XP laptop should not be discounted.
Build your own -- For the ultimate low-power, high-performance home rig, building your own is the way forward. The market is awash with gaming-focused microATX motherboards jam-packed with features to make an ideal mini data center.
However, unless you already have a box of compatible bits, or deep pockets, the cost may be prohibitive. A new i7 rig with 32 Gb of RAM will probably set you back in the region of $800 to $1,000, depending on what corners you are prepared to cut. (Do you really need a gold power supply, liquid cooling?) Bear in mind you'll probably need at least two of them if you want to set up vMotion and other enterprise features.
Dumpster diving on eBay -- Undoubtedly, the best value option is to take advantage of obsoleted servers and high-end workstations. There is a glut of secondhand, out-of-warranty, but still very powerful rack-mount servers on the market. As organizations move to the cloud, servers are decommissioned by rack-full and, ultimately, end up on eBay.
Generation 4 and 5 HPE DL360 servers, for example, are readily available for a tenth of their new cost from four or five years ago. For the price of a bare-boned i3 NUC, you can get a 2x quad-core server with 32 GB of RAM and probably some storage thrown in. Furthermore, these devices are so common, they are usually included in VMware's HCL, making VMware lab setup easy.
However, there are drawbacks. Data center-class devices are large, noisy and power hungry; not the sort of thing you could hide in the corner of your office. These devices are bargain basement for a reason: You literally need to keep them in a basement. However, if you have room for a short 19-inch rack, then practically unlimited power can be yours.
The more practical option is to look for small form-factor PCs. Many organizations (especially in the financial sector) purchase powerful desktops by the thousands and replace them every couple of years. As a result, many small, Intel i5- and i7-based desktops are available. With multiple PCI sockets, SATA storage options and sensibly sized cases, they are an attractive option for the home VMware lab setup. However, because they have a longer useful lifespan, they retain more of their value than more powerful server equivalents. Depending on your thirst for RAM, something really useful can be had for between $250 and $400.
Given that so many hardware options exist for supporting your home virtualization lab, there is no excuse not to get started. With the free edition of the VMWare ESXi hypervisor, and, of course, open source options such as KVM, you can get up and running easily. You can have fast, cheap or quiet; you just need to pick two.
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