Home > Dell, Design, Hardware, VMware, vSphere > Design Exercise–DR or Dev/Test Re-use

Design Exercise–DR or Dev/Test Re-use

In a previous post, I recently discussed some of the benefits of Scaling Up vs Scaling Out (https://vnetwise.wordpress.com/2014/09/28/design-exercise-scaling-up-vs-scaling-out/) and how you can save money by going big. In that example, the site already had 4 existing hosts, wanted 5 new ones, but settled on 3. We can all guess of course what the next thing to get discussed was, I’m sure…

“So let’s reuse the old 4 hosts, because we have them, and use them… for DR or a DEV/TEST environment”. This should be no surprise, that “because we have them” is a pretty powerful sell. Let’s talk about how that might actually cost you considerably more money than you should be willing to spend.

Just as quick reminder, a summary of the hardware and configurations in question:

OLD HOSTS: Dell PowerEdge 2950 2U, 2x E5440 2.8GHz 4 Core CPU, 32GB DDR2

NEW HOSTS: Dell PowerEdge R620 1U, 2x E5 2630L 2.4GHz 6 Core CPU, 384GB DDR3

1) Licencing

Our example assumes that the site needed new licencing for the new hardware – either it didn’t have any, it expired, it was the wrong versions, who knows. So if you reutilize those 4 hosts, you’re going to need 4-8 licences for everything. Assuming the same licence types and versions (eg: vSphere Enterprise Plus, Windows Server Data Center, Veeam Enterprise, etc. ) that works out to be:

  • 4x $0 hosts as above = $0
  • 8x Sockets of vSphere Enterprise Plus @ ~ $3500/each with SnS = $28,000
  • 4x Windows Server Data Center licences @ ~ $5000/each = $20,000
  • 8x Sockets of Veeam B&R licences @ ~ $1000/each = $8,000

Total Cost = $56,000

Total Resources = 89GHz CPU, 128GB RAM

That’s a lot of licencing costs, for such little capacity to actually run things.

2) Capacity

That’s only 128GB of RAM to run everything, and 96GB when taking into account N+1 maintenance. Even if it IS DEV/TEST or DR, you’ll still need to do maintenance. These particular servers COULD go to 64GB each, using 8GB DIMM’s, but they’re expensive and not really practical to consider.

3) Connectivity

Let’s assume part of why you were doing this, is to get rid of 1GbE in your racks. Maybe they’re old. Maybe they’re flaky. Maybe you just don’t want to support them. In either event, let’s assume you “need” 10GbE on them, if for no other reason but so that your Dev/Test *actually* looks and behaves like Production. No one wants to figure out how to do things in Dev with 12x1GbE and then try to reproduce it in Prod with 4x10GbE and assume it’s all the same. So you’ll need:

  • 8x 2pt 10GbE PCIe NICs @ $500 each = $4000
  • 8x TwinAx SFP+ cables @ $50 each = $400

We’ve now paid $4400 to upgrade our hosts to be able to use the same 10GbE infrastructure we were using for Prod. For servers that are worth maybe $250 on Kijiji or eBay (http://www.ebay.ca/itm/Dell-Poweredge-III-2950-Server-Dual-Quad-Core-2-83GHz-RAID-8-Cores-64Bit-VT-SAS-/130938124237?pt=COMP_EN_Servers&hash=item1e7c8537cd). Not the best investment.

4) Real Estate / Infrastructure

Re-using these existing hosts means 8U of space, probably 2x the power required, likely internal RAID and disks that is just burning up power and cooling.

A quick summary shows that we’ve now spent somewhere in the area of $60,000 to “save money” by reusing our old hardware. This will take up 8U of rack space, probably consume 1600W of power, and we’re investing hardware in very old equipment.

But what if we did similar to what we did with the primary cluster for Prod, and just bought… 2 more of the bigger new hosts.

2x Dev/Test Hosts @ 384GB:

  • 2x $11,500 hosts as above = $23,000
  • 4x Sockets of vSphere Enterprise Plus @ ~ $3500/each with SnS = $14,000
  • 2x Windows Server Data Center licences @ ~ $5000/each = $10,000
  • 4x Sockets of Veeam B&R licences @ ~ $1000/each = $4,000
  • 8x SFP+ TwinAx cables @ ~ $50/each = $400

Total Cost = $51,400

Total Resources = 57.6GHz CPU, 768GB RAM

Compared to:

Total Resources = 89GHz CPU, 128GB RAM

So we’ve now spent only $51,400 vs $60,000, and ended up with 6x the capacity on brand new, in warranty, modern hardware. The hardware is 100% identical to Prod. If we need or want to do any sort of testing in advance – vSphere patches, Firmware Upgrades, hardware configuration changes, we can now do so in Dev/Test and 100% validate that it will behave EXACTLY that way in Prod as it IS in fact exact. All of your training and product knowledge will also be the same, as you don’t have to consider variances in generations of hardware. We’re also going to use 2U and probably 600W of power vs 8U and 1600W.

If this is all in one site, and being used as Dev/Test you have a couple of ways you could set this up. We’re assuming this is all on the same SAN/storage, so we’re not creating 100% segregated environments. Also, the 10GbE switching will also be shared. So do you make a 3 node Prod and a 2 node Dev/Test cluster? Or do you make a 5 node cluster with a Prod and Dev/Test Resource Pool and use NIOC/SIOC to handle performance issues?

If this is for a second site, to potentially be used as DR, we’ve now saved $30K on the original solution and $8K on the solution we’re discussing now. This is $38K that you could spend on supporting infrastructure for your DR site – eg: 10GbE switching and SAN’s, which we haven’t accounted for at all. Granted $38K doesn’t buy a lot of that equipment – but it SURE is better than starting at $0. You just got handed a $40K coupon.

So, when you feel the urge to ask “but what should we do with this old hardware, can’t we do anything with it?” – the answer is “Yes, we can throw it away”. You’ll save money all day long. Give it to the keeners in your environment who want a home lab and let them learn and explore. If you really have no one interested… drop me a line. I ALWAYS have room in my lab or know someone looking. I’ll put it to use somewhere in the community .

Categories: Dell, Design, Hardware, VMware, vSphere
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  1. October 2, 2014 at 7:01 AM

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