In my previous post, “Reasons to Virtualize Your Email Servers – Part 1 of 2”, I enumerated three reasons for virtualizing email servers. There are many more reasons why administrators and organizations would want to virtualize their email servers that I will discuss now.

Here are three of those reasons which I discussed in my previous post on why administrators and organizations would want to virtualize their email servers:

1. Understand and learn a new technology.
2. Better use of resources.
3. Lower software licensing costs.Here then are five more reasons for companies and organizations to virtualize their email servers.
4. When your company virtualizes their email servers they are reducing the number of physical boxes that they have to keep and maintain. Email administrators often manage, and administer, other machines besides their email servers. And if your IT department runs as a profit and loss center then administrators should be very interested in reducing the number of boxes they have to administer if they know that they are going to benefit financially. When there are fewer boxes to maintain then your costs are lower. Fewer boxes mean lower cooling costs. Fewer boxes also mean lower power costs as well. Lower power and cooling costs is most likely a part of your company’s goals for a greener environment.
5. Virtual email servers also mean lower hardware costs. Having fewer hardware boxes obviously results in a lot of savings to your company and to your IT department. This can free up money to be used for new software tools or applications for IT administrators and email administrators to deploy within their environment as needed.
6. One of the biggest benefits that you get when you virtualize your email servers is that you – as an email administrator – get more flexibility when it comes to managing the resources that you need to get the best performance out of your email servers. A virtualized server can have resources dynamically added to their operating profile to accommodate unexpected spikes in utilization. Virtual CPUs, memory and even I/O adapters can be added or removed from your virtual email server’s operating profiles as needed. In some virtual environments it is even possible to define different profiles for the same virtual server such that an administrator can switch to whichever profile fits the resource needs of the current utilization rate. Having this flexibility to have a dynamic virtual server can be a great benefit to administrators especially for changing email server loads or when balancing the loads across multiple email servers is not possible. Simply change the amount of resources of the virtual email server to adjust for heavy or light workload requirements as needed.
7. Virtualization of email servers makes it possible to run different versions of Outlook or Exchange in different operating systems. Email administrators can even fine tune those email environments by specifying the different rev levels of the operating systems. Email administrators could test new versions of Outlook or Exchange Server on different virtual servers all within the same physical box. Then, when it is convenient for them, they could roll out the newer versions of Outlook or Exchange into their virtual production environment without needing to reload the OS or the email software onto a different physical box. Simply flip the software switch on their virtual email servers and they are now live in a much shorter amount of time than if they had needed to test, stage and go live on multiple physical boxes.
8. I’ve already discussed the savings in power and cooling that can be realized when going to a virtual email server environment. But there are other infrastructure advantages as well. The number of I/O adapters is reduced which also can reduce the amount of cables and switches that are needed in your data center thus further reducing your overall IT costs. Then there are rack space requirements that can also be reduced. And the assorted peripherals such as video, mouse and keyboards that are needed is also reduced in a virtual email server(s) environment.

In summary, it is very easy to see the advantages for moving your email servers to virtual email servers. The gains that can be realized in maximizing your resource utilization rates, flexible use of resources, operating costs and cost savings in hardware and software should be very easy for email administrators to demonstrate when presenting the virtual email servers advantage to upper management.

5 More Reasons to Virtualize Your Email Servers – Part 2 of 2

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More and more companies are learning about virtualization technologies. And there are a lot of companies that have already gone from a dedicated server environment to a virtualized server setup in their data center.

Companies, IT directors, their staff and administrators are all considering the advantages and disadvantages of virtual server technology and whether it is the right choice for their company. There are many reasons to go to a virtual environment. And when going to a virtual environment a frequent question is which of our servers would benefit from being virtualized?

Email servers are great candidates for virtualization. If your organization is small then you are probably already running your email server or servers on small boxes with a certain amount of CPU, memory and disk drives. One of the parameters to look at when considering a virtual server is to ask the question: what is the current CPU utilization of my existing email server?

Typically, most data centers are running their email servers at anywhere from 20 to 25 percent of CPU utilization. If that is the case for your company, and you have other servers also running at 20 to 25 percent, or less, then you are a good candidate for an email server virtualization effort.

And what does it mean to virtualize my server? In short, a server virtualization means that we are consolidating one or more existing servers onto one physical frame or box. Each of the virtual servers gets their own allocation of virtual CPUs, memory, disk storage and I/O adapters. A combination of software and firmware performs the distribution and balancing of those resources among the virtual servers that have been defined on the physical frame or box. Usually a hypervisor is involved as a sort of traffic cop for distributing those resources.

Here are some of the many reasons to help you and your company make the decision to virtualize your email server(s):

1. The very reason why an email administrator would be interested in virtualizing their email server is because of the potential benefit to their resume. An administrator might be scratching their head at this point and be thinking “but, now I have to learn about another new technology again. It’s going to take more time away from my existing work, it’ll be time consuming and I may not even like it.” But that’s exactly why an email administrator should be looking forward to virtualizing their email servers – because most email administrators also perform system administration. And if an administrator is a good technologist already then getting to learn a new technology, such as virtualization, can turn them into a great technologist. Understanding new technologies, such as virtualization, can only add to an administrator’s resume and make them more marketable in the workplace.
2. Given that most companies are running their email servers at anywhere from 20 to 25 percent of CPU utilization and have other servers also running at 20 to 25 percent, or less, they can consolidate those physical servers onto one box running virtual servers instead. Server consolidation can result in 3 to 1 or even a 4 to 1 server reduction ratio in some cases. The result is that they can get a better server utilization of between 60 to 80 percent. This means that the physical server is not wasting resources. CPU, memory, disk drives and adapters are getting a higher percentage of usage and are thus earning their money so to speak. Why pay for resources that are only used for a small percentage of the time?
3. One of the added benefits of using fewer resources, for multiple servers, is that your licensing costs go down. Let’s say that you consolidated 4 email servers, each with 2 CPUs for a total of 8 CPUs, down to one physical box with just two CPUs – a 4 to 1 reduction ratio. That means that rather than paying for 8 CPU licenses in the dedicated server days your company is now paying for only 2 CPU licenses for your virtualized environment. This is something that an IT department can appreciate and see the value of. It also means that for an email administrator they are no longer administering four physical boxes but one physical box. This results in not only a savings of money but also time, time that is valuable to all email administrators and system administrators in general.

In my next blog post I will describe five more reasons why it makes sense to virtualize your email servers.

3 Reasons to Virtualize Your Email Servers – Part 1 of 2

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One of the great benefits for us in IT is that as hardware and storage prices have come down, and performance has increased, we are more able to offer services that in the past was prohibitively expensive to deliver. Rapid deployment and expansion of service, redundancy, and very high availability are all possible now for a fraction of the cost of a few years ago. Granted, it still costs more to provide such high quality service. Let’s take a look at how virtualization, replication and high availability, impact storage requirements and costs.

Virtualization allows us to deploy servers without tying resources to a single specific hardware system. The images can be moved from one system to another, cloned, made redundant and thereby easily allow expansion of particular applications and services. Virtual servers are a foundation for simple, rapid, consistent scalability. Having several or many identical instances allows us to deliver high availability far more easily. Virtual images do take space, and must run on a base platform, so clearly a single VM takes more space and resources that the same service running on dedicated hardware.

High Availability (HA) is the IT goal of having continuously available service for a particular application, connection or resource. Sometimes this is done via fail-over from a primary to a secondary connection or resource. It is also possible via load balancing. The load balancing can be accomplished at the application layer, at a gateway layer, or via an appliance. Load balancing is also possible at the name lookup level. For the purposes of this discussion we are considering application, gateway, and appliance types of load balancing and fail-over. Application layer mail gateway routing is often built-in to the system, whereby the gateway has alternate choices to try if its primary gateway is unavailable. This may be implemented in different ways depending on the vendor and the service. For SMTP there are underlying standards and requirements for gateway and routing behavior.

Replication of data that changes is key for us to have consistent service in the event of a failure of one of the data storage servers. So virtual images aren’t enough–we need to have the changing data replicated from the primary location to one or more redundant locations, ideally in real time.
Storage requirements obviously go up linearly for every replicated server. If you have a series of servers with the same OS, configuration, applications and local data replicated, you should then have for every n servers you have n times the storage requirements. For three servers, you have three times the base storage requirements. For 10 servers, 10 times the storage needed. Fortunately performance and reliability scale far better than the required storage. Another important factor is that the front end application layer or Web layer doesn’t hold all of the data presented. It should be clear that not every server hosts the directory of email addresses and user identities. And the Web interface doesn’t host the mail messages or the directory–it’s just a front end. The mail messages themselves are in a database, data store, or file store (depending on the mail server, platform and configuration you have picked) and that database can be highly available and replicated, but there isn’t a message store duplicating all messages on every server and replicating them to each one. Instead, the design is usually a central store, perhaps with one replica in a cluster. Similarly there are few directories, often replicated between sites or across long distances to improve performance for lookups by local users.

A very straightforward HA server layout might look something like this: two (or more) servers on the Web tier, two for each of the apps on the application tier, two directory servers and two message store servers for each site. So what might be possible to run on even one server or two in total, we now have eight servers defined, such that we have redundancy at every tier.

HA Cluster Architecture

We then  need to consider base storage requirements for each type of server along with the number of servers we are going to have of each type, in order to determine how much virtual drive space and/or SAN space our servers will consume. As we discover, we always want to budget toward the high end of space calculations, and then put in even more in our estimate for future unexpected situations. For example, on some of the servers we may want or need to take a snapshot of the entire message store to work with, but need to create it locally; so however big in gigabytes our message store is, we’ll need at least that much more room locally to copy or restore such an image. Repair and optimization tools for data stores and databases also may need similarly large amounts of space to work creating temp files or new copies of the data. So, a 15 GB virtual drive might seem big to begin with, but if you build up an 8 GB data store on it, you’re “out of space” if you need to make a copy locally. Consider also if you need to restore from a backup and don’t want to delete the in-place store. Of course, often such work can be done on network drives, but again be warned that disk performance will be much higher locally.

Many of the clustering and distribution of services concepts are available within Microsoft Exchange and are integrated into the application suite, but it’s worth it to understand how these ideas work independent of just a single messaging platform like Exchange.

Virtualization, Replication, Storage and High Availability

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Can you make your email greener? Possibly.

With the release of Microsoft Windows Server 2008 with Hyper-V and Microsoft Hyper-V Server 2008, a virtualized Exchange 2007 SP1 server is no longer restricted to the realm of the lab; it can be deployed in a production environment.

So says Microsoft in the Exchange Team Blog. Yup, it’s now possible to virtualize Exchange Servers while continuing to be entitled to support from Microsoft. But there’s good news and bad news here. The good news is that virtualizing Exchange can offer real savings. In one of the examples that Microsoft cite (with 7 servers being consolidated to 3 servers running 7 virtual servers) the potential energy savings are estimated at 25,754 kWh or $22,516 per year. On top of that, there’s also savings to be had on hardware and, if your utility company has a high tech incentive program (as PG&E do) you may even be able to recover a portion of your project costs. Woohoo! So, not only can you cut your costs, but you can make your operations a bit greener in the process.

But here’s the bad news. As Microsoft put it, “Due to the performance and business requirements of Exchange, most deployments would benefit from deployment on physical servers.” What that really means is that most Exchange deployments will not be suitable candidates. Microsoft provide the following 3 scenarios in which virtualization is worth considering:

• Small Office with High Availability
• Remote or Branch Office with High Availability
• Mobile LAN

But even in these scenarios, virtualization may still not be the best option. It really all depends on how heavily Exchange taxes its underlying hardware – virtualization is only the right way to go if your servers are underutilized. The technical checklists contained in the blog post (see link above) will help you to determine whether or not your Exchange Servers make for good candidates.

But if you think that your Servers may be suitable for virtualization, it’s certainly worth exploring the possibilities as the savings can be substantial.

Greening Exchange Server

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