Home vSphere lab, virtual or physical?
This is a question that a lot of people ask on the forums (the ones I frequent are TechExams.net and the VMware community ones) – virtual or physical. I wont go into details about building a lab, this is about taking a look at both types of labs, their advantages, disadvantages and related things.
- Some kind of beefy physical computer. As long as it has considerable grunt (upwards of 16GB RAM) you are going to be just fine.
- Ensure the physical computer you have supports VT-x and EPT (if Intel) or AMD-v and RVI (if AMD), the first feature is required for the hypervisor and the second one’s needed to support nested ESXi. For an Intel processor, check this link. For an AMD processor, check this link.
- Any dual-core and upwards processor is going to just fine (for most people). If you are going to have multiple nested ESXi servers, 2 or more vCenter’s and lots of other bits and pieces, an i7 or similar processor will be needed.
- Disk. Get an SSD or two at a minimum if you have a desktop. If you have a server, fill all disk slots with SAS disks (10k or 15k are both good and bigger the better).
- Software SAN. I’m a staunch supporter of Starwind’s free iSCSI SAN. Awesome product, easy to install and personally I’ve never had a problem, ever. OpenFiler, MS iSCSI also work too.
- Any home lab is likely going to constrained by disk more than anything else. CPU is almost never the bottleneck. RAM can be a possible slow point too, but prices have dropped considerably to allow you to max out your mobo. So stock up on disk.
- Continuing the above point, if you will be writing and reading off the same disk(s), it’s a given the performance is going to be less than stellar.
- Numerous nested ESXi hosts. A virtual lab does not limit you to a specific number of hosts as you are only limited by the grunt in your physical computer. This is clearly the biggest benefit, you can easily have 3-4 (or more) ESXi hosts and play with HA, DRS, Host Profiles, Storage DRS, vMotion and all the rest of the cool stuff to your heart’s content.
- Power savings. You are running one machine only, obvious power savings right there.
- Less clutter. Again, with one machine only there’s no need for a rack, much cabling or cooling and there are fewer moving parts.
- Spin up/destroy VMs at will. Fewer things can go wrong with fewer moving parts.
- DPM (no WoL for your nested ESXi hosts), EVC, FT won’t work.
- Disk. I know I’m repeating myself, but a nested lab’s pain point is disk. Just ensure you have an SSD or plenty of SAS disks to ensure the IOs are spread across multiple disks. Don’t RAID your disks, it’s a lab right. The maximum performance’s going to come out of RAID 0, so leave the disks on their own.
- One disk failing can take out multiple pieces of your setup depending on what was on the failed disk.
- Any computers that support the same features a virtual lab needs. (see above). At least 2 such computers, you’ll probably need 3-4 to get a decent lab going.
- Shared storage. You are going to need some kind of shared storage, there are tons of threads on the Internet for a SAN for a home lab. Here’s a good one for a physical lab. Good read.
- Physical switches. Preferably ones that do VLAN’s and jumbo frames so you can play with these two. Probably get two switches so you can stack them and play with LACP etc
- Rack. If you are so inclined, but I’d just sit them on the floor or on a sturdy table.
- A home physical lab is going to be constrained by the number of hosts you have. RAM and CPU are very likely going to be no problem at all.
- Cost. A physical lab’s easily going to end up in the $2500+ range or more depending on the gear you get.
- It’s the closest you’ll get to a real world setup.
- You can have DPM, EVC and FT going in a physical lab.
- Power consumption. With multiple devices powered on, you could see significant power bill increases.
- Higher chance of failure with more moving parts.
- Noisy and increased space usage.
- Increased cabling and cooling requirements.
Decision: Virtual lab.
Multiple nested hosts, cost savings and low noise clinch it in favour of a virtual lab in my opinion. For a realistic look and feel of ESXi, a physical lab is the way to go.
Feel free to comment below!