planning a server farm

8/8/2019 Planning a Server Farm

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(http://www.windowsnetworking.com/articles_tutorials/Planning-Server-Farm-Part2.html)

Planning your Server Farm (Part 1)

In this series of articles, we will cover all that you will need to consider when planning to

deploy a new server farm. A server farm is just lingo used to describe a grouping of serversthat you use within you Local Area Network (LAN), usually tied to a high speed backbone if

designed properly. In this article set we will look at considerations when deploying a server

farm. These tips and tricks will no doubt help you if you are unfamiliar with planning a

design, ordering such equipment and deploying it.

Apr 27, 2005

Introduction

It¶s very important to always plan and consider design when you do just about anything inyour life. If you want to get a new bank account, you research what you want and select from

options what best suits your needs. Buying a mobile telephone service is very much the same process, but at a different scope, instead of worrying about what accounts you need

(checking, savings), you are worrying about different things, such as Phone type that servicesthe needs you want, as well as the provider¶s services, what do they offer and what does their

competition offer? When designing a server farm, the amount of information needed, planning and design is unbelievably multiplied, especially if the size of the company you are

working within is at the enterprise level with a global reach. How do you plan for access intoyour server farm to gain resources? Where do you place it? What are some of the

considerations you should take into account? In this article we will cover as much about

planning as possible, although each network (and situation) is unique ± these tips are fairly

generic and can be used in any company¶s network, just make sure you tailor and tweak your plans beyond this article if you are deploying a real server farm.

What is a server farm?

As explained before, a server farm is nothing more than a µgrouping (farm) or servers¶. A

more technical definition: A server farm is a group of networked servers that are housed in

one location. Another way this term has been seen and used is when related to Clustering and

Load Balancing. Clustered and Load Balanced servers when configured correctly, will

streamline internal processes by distributing the workload between the individual components

of the farm and expedites computing processes by harnessing the power of multiple servers.

For failover scenario¶s, when one server in the farm fails, another can step in as a backup. Inany case, we will look at the design of both.

The Team

A server farm deployment is a large scale process, taking many team members, many

different groupings of technical expertise (systems, development, project planning, technicalsupervision and management, networking, security«) all of which should be involved in the

design and deployment of the solution. You should also know before-hand who will be



managing the solution. You should also ensure that your team not only knows how to deployit, but also has ongoing training on it for support. Since there are so many components to a

server farm, its essential that you have help desk support if you have clients that rely onresources within it. For instance, if you have two nodes in a cluster and one fails, the clients

may experience slowness in the applications or data they were working with, for that reason,

they would need a place to call if problems were to come up, that has to be planned as well.

Calls coming to the help desk need to be routed to the correct person and µslowness¶ may be perceived as a network problem. Because of this, it's imperative to have ongoing support

analysis, training before as well as after the deployment in key areas.

The Plan

The plan is the key to your success. Great things come from great plans. It's a great way to

pre-think what you need and get it done. Consider what goes into building a home or office

building. The same level of care, effort, technical expertise goes into building a network. In

some cases, depending on the size of the network, building a global network could be

considered a chore compared to walking across 100 feet of blazing hot coals. All jokes aside,

plan your deployment first, then deploy once you have your budget, resources and timeline inorder.

Documentation

You need to either have preexisting documentation, or create new documentation. You

cannot plan a design without drawing it. You need to get this design to the rest of your team

members; things brought up in conversation with them may alter the design. Make sure you

have working documentation while you plan, deploy and after.

The Layout

Now we get into the meat. Let's consider all the pieces you would commonly see on a

computer network and let's build them into a server farm. These are the current resources:

y 25 Servers and 500 Clients

y Internet access and possible Proxy use, URL filtering

y Firewall protection at Internet access

y Gateways

y Routers in use

y Switching in use

y Remote Access Services (Client VPN)

y Naming services such as DNS and WINS

y Logical Addressing services such as DHCPy Database services

y Application services

y Mainframe with ERP Software

y Mail services

y FTP services

y NAS services

y SAN services



y File and print servicesy Fax services

y Web services

Please note that there may be more services to consider in your organization, please make

sure that you do spend the time thinking about them and adding them to your own list that

you can develop with the help of this one as a starting point. In the following illustration, youcan see how I laid out the design for this company¶s server farm.

Tips to Consider

In this section of the article,

1. You have a main hub site; this is obviously where you want the bulk of your

resources. Out of all the services listed, the company where the server farm is being

implemented is in the Main NY site. Remote sites are Tokyo, Korea, UK and Italy.

There are 25 users per remote site and the bulk of the remaining are located at the hub



site. Obvious placement for the server farm would by in NY, where the mainresources are.

2. The main resources are 6 Windows Server 2003 servers that all run the following.You have a clustered File and Print Services solution that allows redundant access to

data and printers 24 hours a day. If a server fails, then the other one takes over for the

failed node. This is called 'failover'. You have 2 Domain Controllers, both running

Active Directory, DNS (Primary and Secondary). You have one WINS server. Youhave one DHCP Server and you have one Intranet Web server.

3. The 6 servers (although the cluster could be considered a farm in itself), are all added

to one VLAN on the Layer 3 switch in the core of the network. This switch acts as a

router as well, so this switches¶ router is the default gateway for the LAN. This makes

this set of redundant switches, the 'switching core' of the network, or 'the backbone'.

The backbone is nothing more than a concept in speed« the center of your network

should be the fastest, with the least amount of policies to hold you up, slow you down

or causes 'any' delay whatsoever. Keeping servers in a single VLAN could be

designed for enhanced security.

4. You should have your backbone analyzed for what traffic really traverses it. Manyswitches have intelligence built in (or many network management products) that can

tell you what percentage of bandwidth you are using. This is helpful in the design because you can start in the core (backbone) with Gigabit Ethernet running at 1000

Mbps, then have client access set at 10/100 Mbps. Access to your servers is not goingto be the bottleneck. A bottleneck is the same as trying to push a basketball through a

garden hose, the amount (or pressure) of the data coming in cannot be pushed out fastenough and serious issues could occur from this. Make sure you design the LAN

speeds correctly.

Summary

In this article, we covered the fundamentals of what needs to be considered when building out a

server farm. In this article we learned that it's important to plan and design, have the right people on

the job, have a plan documented, and then deploy. Once deploying, consider other things such as,

every network is different so there are many categories you may find or dig up that are specific to

you. Make sure you keep your eyes open for that. We also covered server placement, logical design

at the high level and switch and network design. In part 2 we will cover the server room build out,

racking and other tips to help you build out a server room and server farm.



Planning your Server Farm (Part 2)

Welcome to part two of how to plan your server farm and other tips to consider when

building Windows Server 2003 systems to serve your network users. Deploying a server can

be a chore, especially when it comes to planning. There are many things to consider. In this

article we will look at how to verify your plan, and then move on to OS software checks andupdating, as well as reviewing power requirements.

Apr 27, 2005

Installation Planning

Now that you have initially figured out where you want to place your server farm, we need to

get to the nuts and bolts of actually planning it. To have a good server farm deployment you

will need to carefully plan. Note ± not planning may cause you a lot of problems which could

lead to the server farm never becoming a reality. You will also need to put some time andthought into the size of the deployment ± its complexity, how much equipment you are going

to deploy and so on. In part 1, we covered placement and the bare essentials, gathering your

team and so on. Now, a detailed plan of the installation should be your first step. This shouldhappen no matter what, every time you plan, regardless of the size and complexity. Why?

Simple ± because if you do not plan then you will spend time you don¶t have (I know) fixing

very stupid oversights and errors that you could have avoided completely had you spent the

time up front doing a little planning.

Eliminating any time spent correcting oversights and fixing compatibility errors should be

your goal. In the next few sections we will look at some of the things that you can incorporate

into your plan, although ± this is by no means a definitive list. All network environments are

unique in their own ways. Because of this fact, you will need to adjust your plan. Use thisarticle as a start and make sure that you build on to this list and append any special additions

to your plan.

Building a Project Plan

You can build a project plan with a simple Gantt chart. You can use a fancy program like

Microsoft Project, or you can use a simple Spreadsheet or bulleted Word Document. A

project plan can help you plan, it¶s that simple. It helps you to track your resources and make

sure you have a viewable way to track a project and its deliverables. In the illustration below,

you can see a sample worksheet in Excel that I was able to download from Microsoft to help

me plan a DFS deployment. Hey, it's free and already done ± you only need to fill in the blanks and it's easy to add to it too.



There is a Job Aids section on the Microsoft site that I left a link to in the Reference and

Links section at the end of this article. Remember, the plan is only there to help you to deploy

a server farm and how to keep track of it. It's up to you if you want to make one or not,

although it's highly recommended so that you do not waste your time. Deploying Server

farms are almost always costly, and almost always time consuming so a good plan will

hopefully eliminate any waste in both areas.

Hardware and OS Compatibility

Now that you have the plan in place, you need to consider a few things about the individual

systems, the servers themselves. All hardware that you will use will most likely need to be

checked for updates. As well, any software you install will also need to be updated. Every

driver installed « most likely needs an update. My point here is ± get in the habit of just

checking and updating everything every time. If you stick to this method, you will never

forget to update anything, and because you are µchecking¶ first, you will never ruin anything

by accident. The next point is ± you never want to install a driver or any other patch on a livesystem without doing it first on a test system. If you do not have an SLA in place and are not

concerned about downtime then it's your prerogative to update away, but it's a good idea totest software updates first before you install them. Over the years, driver and software

updates have gotten much better, but if you are deploying 15 Windows Server 2003 systems

in a preexisting Server farm« it may be wise to test the updates first.

If you are going to update hardware chips, make sure that you do not power off the system

for any reason during the update. Any interruption to the process will render the device

inoperable. Before installing a new operating system, or upgrading an existing one, it's

important for you to verify that compatibility exists between all internal and external

hardware, and any associated add-on components, peripherals and so on - planned for thenetwork. One of the most common ways to ensure this necessary compatibility is to check the

OS manufacturer¶s Hardware Compatibility List (HCL).



The HCL is basically a list, supplied by the manufacturers of major operating systems, of hardware that has been tested and verified to work with their Network Operating Systems ±

of NOS for short. Checking the HCL is an important consideration when purchasing server hardware because it will determine what hardware you want to choose, as well, you can

check to see if there have been any compatibility issues so you can avoid them entirely. Keep

in mind that while Microsoft used to rely heavily on a hardware compatibility list in

identifying which equipment was known to be compatible with their various operatingsystems, the comprehensive reference is now called the Windows Catalog.

If you are not compatible, you must check to see if you have enough hardware in your system

to support the NOS. The NOS will require a very specific recommendation. Make sure that

you meet this recommendation and exceed it based on a true estimation of your current and

future workload. This would require that a baseline of system performance be done so that

you know. Since it's impossible to test a system you are planning to buy, this is why there are

minimum requirements also tied into the add ons that you will run, such as if you were to

install an e-mail system on one of your servers ± this of course would mean that you would

need 'more' disk space, CPU power, Memory and so on to run the new service. All this must be taken into consideration before you plan your server farm. Windows Server 2003's specific

requirements are listed in the Reference and Links section of this article.

Driver and BIOS Updates

Now that you have installed hardware that is compatible, you must update it. Update your

BIOS, your hardware (such as SCSI controller cards), and all your hardware you haveinstalled on the Server. Once these devices are installed and running properly on your server,

it should be no problem to download any other necessary drivers and install them (or updatethem). Just be careful when downloading and verify your source so as not to download a

Trojan or some other form of malware.

Make sure that you update everything that can be updated. When conducting an installation,the technician should always use the latest drivers for the system's devices and again if this is

a system already in use, make sure that you test the drivers first on another system before you

do the upgrade. You may update the Video drivers and then not be able to access the system

because you can't see the console anymore.

Hardware Standards

Make sure that you match all your hardware. I suggest always using a vendor when buying a

server; home built PCs can serve a purpose, but they usually lack many of the hardware

enhancements that a server class system will bring you. In any case, if you go with a vendor,

try to make a partnership with that vendor and try to keep all your hardware updated. For instance, when planning a server, hard drive controllers must be matched properly with thetypes of drives they support. The SCSI host adapter or the IDE/ATA controller normally

interfaces between the system and the hard disk drives. ATA controllers are designed to work with IDE drives and SCSI controllers are designed to work with SCSI drives. This is how

they are laid out and they usually do not mix well, problems usually occur.

Checking and Verifying Power



Make sure that you plan your power requirements very carefully. When working in theenterprise, it's always easy to overlook what is always there« power. You must have power,

always. There is no way you can survive without it so you have to plan for it. If power goesaway, then the Server turns off. It's that easy. There are also varying levels of 'losing power'.

You can have sags, surges, spikes and so on. Power variations can be the source of many

server problems and power fluctuations are common. This should pretty much tell you that

you really should use some form of power protection on your systems ± too many surges to a power supply in your server may render the system dead when you least expect it. Some

variations can cause the computers to shut down and reboot, causing loss of data not saved to

disk or worse, leave your system unrecoverable. There are articles in the Reference and Links

section of this article that help you plan for recovering from that happening.

The power in a new server farm room should be tested extensively, thoroughly, completely

and reengineered if needed before any computer equipment is installed. As well, an

electrician should be contracted to do the job, one with experience testing systems to their

faults. The AC voltage level should be tested and monitored to determine whether it is stable

under no load conditions. In the United States the AC voltage level should be 120 volts. InEurope the AC voltage level is 230 volts. Check your country for your specifics and ensure

that you apply the same rule. The ground connections of the power system should also bechecked for continuity back to the facility's main ground connection and ensure that it's a true

ground. These are some guidelines and tips you can follow, but in sum, make sure that your server farm is placed in power protected environment. You can use a surge protector, but this

is not recommended. I personally wouldn't even use one on my home PC. Most surge protectors are made so that if they take a surge, they pop, but break in a way so that the power

strip can still be used although there is no more protection. Since I don't get an email from my

surge protector telling me it has been tripped, I don't know and therefore the next surge that

comes may damage my PC.

As well, some that are even more high tech still allow failure. Surge protectors will not

protect the computer from small surges, which are very dangerous to computer equipment.

They will only protect it from very large spikes in power, and may fail to cut power fast

enough to protect the electronic system. An Uninterruptible Power Supplies (UPS) will

provide surge protection and supply power in an emergency (such as a complete loss of

power) - It will also be there for you in emergencies to prevent data loss when the power goes

out, data in memory, etc will be protected.

Uninterruptible Power Supplies (UPS)

In the typical Uninterruptible Power Supply (UPS), operation is very simple. Power comes inand power goes out. Servers are all connected to the UPS and the UPS is plugged into the

wall. The UPS will supply power to the Servers, the UPS will receive power from the

commercial power source. Now, if the UPS has been tested and is operational, charged andready ± if you unplug the UPS from the wall, then the servers should all stay running because

the battery inside the UPS is maintaining power to the servers. Albeit, only for a short time,

but they are still running. Running long enough for the automated shutdown process you can

configure on some UPS system to take place ± or, to shut down manually. Either way, the

server (and its data) is safe from power hazards. This type of UPS is simply a battery backup

system that will keep the system running and permit the system to shutdown normally in case

of a power failure. This type of UPS serves only one purpose: to stop the loss of data if there

were a major power failure to take place.



Backup Generators

If there are blackouts where the power goes out for extended periods of time, a backup

generator will be needed to keep power running to your server systems. If you do not have a

backup generator, you are only going to be able to survive for as long as you have UPS

battery life and that is not meant to be long. A UPS system is meant to 'protect', whereas a backup generator is meant to be able to sustain the load of the network and its systems during

a continuous power outage. Many are operated on gasoline or diesel fuel so it's very easy to

get and use. Of course, enterprise systems will have much larger (and much more complex)

generation systems (like a Hospital for instance).

Summary

That wraps up our two part article on Server Farm Planning. I hope that this served you well and

helped to alert you to things that you may want to consider when planning your server farm. Please

use the following articles to help in your planning as well.

planning a server farm

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