Computing at Home

INTRODUCTION

This article is a review of the advantages and pitfalls of buying commercial computer servers for home use. Why buy a new desktop computer when you can purchase a surplus corporate fast server for much less?! This article is based on my experiences running commercial systems at home. I hope the advice is useful for anyone contemplating purchasing surplus commercial systems for home use.

Over the years I've had several commercial computers that would normally be used in corporate data centers. I've owned a "baby" IBM System/36 that was purchased at a fabric sale. One of my employers donated a Pyramid (quad R3000 CPU) office server tower and disks for which I had to hire a truck to take home. I've also purchased several IBM servers to learn the differences between a commercial processor and a computer you buy for home use. Similar to the differences between a Lenovo ThinkPad for corporate use and an IdeaPad for consumer use. The ThinkPad has features that are meant for a reliable, long corporate life and hence has a higher cost than its consumer counterpart.

These learnings were handy in my work as it allowed me to understand how these servers are used in data center environments. In one job, I was asked to fix an audit finding due to server management Ethernet ports being on the production network. I knew that servers typically have three Ethernet ports; two for production data movement (or only one as needed) and another for managing the server. These should be on two separate isolated networks; production and management zones.

I was interested in virtualization and was looking for computers that could run the VMware hypervisor. This requires the Vx capability supporting virtualization that most modern processors have. When I started to experiment with virtualization, the available commercial processors were Intel Pentium IIIs and early generation Xeons; which lacked the virtualization capability. More modern systems such as IBM's x440 eventually had processors supporting virtualization.

Corporations frequently dispose of their computing equipment every 5 years, as the equipment is fully depreciated by that time. As well, it becomes more difficult for older systems to maintain compatibility with emerging operating systems.

The result is equipment turnover, with many computers shed to the surplus market that still have many years of usable life left. Because of the sheer volume of surplus systems, these end of life systems can be purchased very reasonably.

With personal computers costing many hundreds of dollars, surplus servers, by comparison, can be purchased for a couple of hundred dollars. My personal experience started with buying two IBM x232 e-Series servers for $125 each. These were early single Pentium III based systems that ran Windows Server 2000 but had no virtualization capability. Subsequently I upgraded to an IBM x440 (quad CPU) server for $200. I had also purchased a couple of Dell PowerEdge 1850 blade servers for $50 each from the same surplus dealer. For those with a tight budget that want to experiment with these systems, as in virtualization systems management, or experimenting with RAID configurations, these provide an economical option to purchasing desktop computers.

The same scenario applies to corporate laptops and desktops that after a 5 year cycle, they are surplus. This explains the relatively cheap cost of older laptops on the surplus market. The saying goes that "Intel gives and Microsoft takes"; meaning that as computers get faster, software gets more feature bloated and consumes more resources. After five years, a corporate laptop is no longer as fast due to operating system upgrades, patches, new features, etc.

IBM X3650 M4 Server (2U)

OBSERVATIONS

Noise

My first observation when running commercial servers at home was the noise! This was particularly bad on the Dell 1850 servers which are 1U in height. Note that "U" is a measure of how much frontal height a server takes in a 19 inch wide server rack (1U = 1.75", 2U = 3.5", 3U = 5.35", 4U = 7"). Commercial servers are mounted in racks at a data center and came with various frontal heights; from 1U to 4U.

Servers that are 1U in height have to move a massive amount of air to keep the processors cool. This requires many small fans spinning very fast; remember that the server is only 1.75" high and many electrical components (CPU, memory, video, power supplies, etc,) are densely packed into that space. As a result, the fans spinning at high speed cause a lot of running noise. It's not something that you would keep running overnight due to the noise. The Dell 1850s were eventually scrapped as they could not be left running due to the noise. This was something I did not consider when purchasing these servers.

(2U) IBM xSeries Server Fans

The 2U servers I subsequently purchased are quieter as the fans are bigger and don't have to spin as fast to move the air needed to cool the components. If the internal server temperature becomes hot, the fans will spin faster to improve the airflow, thus increasing the noise further. When these servers startup, they momentarily spin the fans to full speed. Note how noisy it can get if the server starts to heat up; the fans will increase spin to move more air over its components.

My experience has been that in a large open space, there is enough ambient volume that the servers don't overheat and can be left running overnight with only a moderate hum of background noise. The same can't be said if the server is in a small office with the door closed; as the ambient air temperature increases, the fans spin faster to cool the components, but with a closed door, the computer keeps warming the air, the fans spin faster and this becomes a cycle whereby the fan keeps increasing spin to compensate for a room temperature that is getting warmer. Eventually this can damage the server or force a shutdown.

Even with a 2U server, noise could be an issue.

An early system that I owned was an IBM x440 quad processor server. It was a 4U unit and it was the quietest system I owned, the difference being that it had several large fans. As the fans were much larger they could move a fair amount of cooling air without requiring fast spinning. This system could be left running continuously as it only produced a light hum.

The learning here is that the taller the system, the quieter it is due to the fan size and its ability to move air without a high spin speed.

IBM X3650 M4 Server (2U)

Physical Environment

As mentioned previously, these servers generate a lot of heat. If they are to be run in an environment without air conditioning, there should be sufficient room volume that the heat is dissipated with the ambient air. I have two servers; a Dell PowerEdge 2850 and an IBM System X3650. The 2850 can run dissipate anywhere from 524 BTUs/hr at 277 Watts (British Thermal Units) to 2388 BTUs/hr at 1188 Watts. A fully loaded 2850, as I have, with 6 SCSI disks and full memory, is probably dissipating 2300 BTUs. The X3650 is also fully loaded and generates 4053 BTUs/hr at 1188 Watts.

The lesson here is that there must be adequate physical space for these servers to dissipate the heat. Likewise, these servers consume more power than a desktop computer; as much as 1100 Watts versus 450 watts for a high-end desktop computer. Compare that with 90 Watts for a laptop. Anyone running multiple servers will need several 15 Amp power outlets.

Electrical power consumed by computers is almost 100% turned into heat. The conservative estimate is that for every watt, 3.41 BTUs of heat are created. Therefore a server consuming 1000 Watts of power, generates 3410 BTUs of heat. Recall that these servers are meant to be run in air conditioned computer rooms.

Operating Cost

It is more costly to run these commercial servers than it is to run a high-end desktop computer. The obvious one is the power consumption. At 1100 Watts/hr versus 450 Watts/hr for a desktop computer, and current electricity rates, it's like running an electrical heater; it's costly. The other aspect is the ECC (Error Correcting Memory), which is more robust, but more expensive to expand. Desktop computers don't use ECC memory and are therefore more cost-effective to expand.

IBM X3650 Server

The other factor is disk storage. Commercial servers accommodate multiple high speed SCSI disks spinning anywhere from 10,000 to 15,000 RPM. Both the X3650 and the Dell 2850 accommodate six SCSI disks within the chassis, most desktop computers have at most 2 SATA high capacity disks. The SCSI disks are more expensive to acquire, as well more of them are needed if RAID is enabled on the server. Whereas desktop SATA disks have high capacity, the SCSI disks are fast, but have a lower storage capacity.

So, why buy a commercial server for home use?

Advantages

• Low cost to acquire ($50 to $500).
• Reliable features such as ECC memory, redundant power supplies, RAID disk, server management interfaces, etc.
• Modern Xeon CPUs, high speed memory buses and fast SCSI disks.
• Large memory capacity - an IBM X3650 M5 server can have as much as 256 GBytes of memory.
• Ideal for running 24 X 7 applications requiring high availability
• Remote server management and monitoring capabilities.
• Built-in diagnostic facilities.
• Multiple Gigabit level Ethernet ports.
• Removable disks give it the ability to run multiple operating systems, by swapping in/out disk sets. For example, a set of disks for running Windows Server and another set of disks for running Linux. Most 2U servers have at least six removable disk slots.
• Ideal for hands-on learning. Configuration, operating installation, RAID configuration, management, etc.

Disadvantages

• High operational cost - power, heat, components such as memory and disks are expensive.
• Environmental factors - high noise and heat generated.
• Limited operating system support - usually requires server level operating systems, not desktop Windows ready. Some Linux versions may run well. However, more current operating systems may no longer have compatible drivers for older server hardware.
• Higher power consumption means costlier hourly operating cost.
• Older commercial servers can be very cost effective but do not compete well with modern desktops. For example, an IBM xSeries 345 has only 4GBytes of memory and dual CPUs at 2GHZ. Know the specs you need before you buy.

SUMMARY

If the goal is to be an Application Service Provider (ASP) whereby you need a service to run reliable on a 24 X 7 basis, then the solution is a commercial server as it provides the redundancy required to provide a service reliably.

For example, at one of my jobs, I needed an application to manage my team's activities. My employer agreed to buy it. This was a web based application that allowed people to enter their work activities. Technology and business managers could then review the group activities in real-time and use that information to prioritize activities efficiently. Unfortunately, we ran into an issue with having the application hosted in the firm's data center. There were no servers available for our team and worse of all, the deployment team didn't approve the software as it had not undergone a security review.

Instead, I hosted the software on an IBM eSeries x232 (2 X Pentium III CPUs) server at home. I used a Netscape Certificate server to generate an SSL certificate so that any communications between my employer and the home server was encrypted. Staff would login from my employer to the home server over the Internet and manage their tasks over the browser based application. This service was available 24 X 7 and served a staff of 7 over a year. The SSL encryption slowed down the server a bit, but it was still usable. IP source address filtering on the router ensured only the company's IP range was allowed to connect. This is the ideal scenario for needing a commercial server at home.

If the goal is to use a server as a desktop replacement, it is not the best use of these systems due to the reasons already described above. However, it's a great way to learn how these servers are constructed and the features they provide above and beyond what you would experience with a desktop.

Compiled on 07-03-2023 05:17:33