 |
| No items matching your keywords were found. |
Machines Routs
Virtual Machines for Small Business
Virtual machines (VM) have been gaining more and more traction in the enterprise and small-business worlds, with one question often being asked:
"How can virtual machines help my small business?"
It is an open-ended question, and one not easily answered. The specific application of virtual machines often depends on the needs of each particular business. In most cases, however, virtual machines are extraordinarily useful for making sure that the maximum amount of resources are being used in the most effective fashion. By segmenting one server into multiple VMs, an otherwise underutilized server can be parceled out into two or more servers specialized into certain applications, making maintenance and troubleshooting easier as well as using all of the resources of a server that might otherwise stay mostly dormant.
Building A Virtual Infrastructure
For example's sake, let's take a typical entry-level server for a small business:
Processor: Intel Xeon 2.4 GHz
RAM: 4GB
HD: 320GB single SATA
Two Ethernet NICs
Let's also assume our sample small business has one of these server in-house, and they plan to use it to host their Exchange email, Active Directory, and file sharing. They are access Internet via a business cable line, and they have a small LAN serving a ten-person office. In a normal configuration, the server would host an instance of Windows Server 2008 with Exchange and Active Directory. This is a perfectly acceptable configuration, and most IT departments would stop there with their mission accomplished.
Enter the Hypervisor, a free software from VMWare that, for only 32MB of overhead RAM, allows an IT department to segment one server into multiple servers, each with their own form and function. In the example above, the single install of Windows Server 2008 is using very little of the system's resources, especially for such a small office. There are a great many creative uses for the rest of the resources, including the creation of several small Linux VMs for specific functions like file sharing and virtual routing. Here's an example of a simple starter virtual infrastructure:
VM1: Server 2008 + Exchange, 318GB hard drive space, 3.5GB RAM
VM2: IPCop, 256MB RAM, 2GB hard drive
In this tame example, we have added a very small virtual machine to the mix - IPCop, a powerful routing operating system that turns the VM into a commercial-level firewall and router, capable of running DNS, VPN, DHCP, and a handful of other services. IPCop offers a very powerful routing and firewall solution normally found only in high-level routing devices. The hundreds of dollars in savings that resulted from using this versatile utility is simply a single small application of VMs in a small business infrastructure. Instead of running a dedicated PC or device for your firewall, a small virtual machine takes care of the task by using server resources that would otherwise stay idle.
Some network administrators even advocate splitting the server into VMs for each type of function. A real-life example that I worked on involved a dedicated VM for file sharing, networking services (VPN, DNS, and DHCP), email, and other similar applications. The hidden benefit this type of fragmentation is that problems are much easier to isolate than on a single server running all services. Is your VPN not working because of that registry hack you used to fix the email server? Is your Active Directory service fouling up because of the faulty file sharing? The segmented VMs allow for precise identification of problems, and fewer variables in determining the cause of the problem.
Pitfalls of Virtual Machines
The most obvious flaws of virtual machines are that they a) create massive dependence on one single hardware machine, and b) they actually increase resource usage. Let's address each:
While it is true that the VMs all depend on one server, the recovery time with proper backups should be minimal. Since each VM can be saved as an image, recovery only involves re-installing the image and reloading the virtual machines on the physical server. While a lengthy process, it is comparable to the recovery process of a regular, Windows Server 2008 workstation.
The increased resource usage is a symptom of improper monitoring. If one of the VMs is starving for resources, it's easy enough to re-allocate RAM to it from another, and with proper monitoring and care you can have very minimal waste of resources on an virtual server. A properly mapped out and configured hypervisor will not misuse resources, and in fact will used them more effectively than a dedicated machine.
In the end, then, virtual machines are a great way to wring out a little more versatility from a server. Even if the machine is just a hypervisor running one VM, the ability to expand on demand and segment your infrastructure virtually is an invaluable tool that can turn an underutilized server into a service powerhouse.
About the Author
Want to learn more? Boris Tulman writes for Good Networking (goodnetworking.com), a hot new blog that offers computer networking tutorials, networking tips and best practices. Looking for a good networking tutorial? Please visit Good Networking and find what you are looking for!
Can anyone tell me the audible frequency of a fax handshake tone?
I work on a very busy switchboard that services in excess of 6000 voice extensions and a large number of fax machines. We regularly get mis routed fax calls to the switchboard because fax users mis-dial the distant fax, and I wondered if these fax handshake tones could contribute to acuostic shock.
The tones are around 1200 hertz.
There is no such thing as "acoustic shock" and just because you have made it up doesn't mean a thing.
Crossole - Listening Machines 2011 GTCMT
Tags: No Comments
0 responses so far ↓
Like gas stations in rural Texas after 10 pm, comments are closed.