Switches & I/O

Why Buy Real KVMs, When Virtual KVMs Will Do?

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By: Ed Tittel (7/28/2010)

KVM stands for “keyboard, video, and monitor” and describes hardware devices that enable IT professionals to interact with, and operate remote devices (servers, mostly) that may lack all of these items. A virtual KVM extends the concept further and uses remote network access so a desktop or notebook PC provides the keyboard, video, and monitor inputs and outputs for network attached devices. Real KVMs cost money, sometimes substantial sums; virtual KVMs are cheaper, if not free. Savvy CIOs and IT professionals find them useful, functional and affordable. In most server rooms and in nearly all data centers, KVMs are often built into one or more server racks. These generally take the form of 1U slide out drawers, with pop-up monitors and slide-out keyboards; they also include wireless or wired mice to support pointing and clicking on GUI interfaces as circumstances so often require when installing, configuring, managing, or troubleshooting servers, routers, switches, and other typical computing gear. For example, Dell offers various 1U KVM consoles that incorporate 17” flat screen monitors, keyboards, and touch pads (in lieu of an actual mouse) that integrate directly and easily into standard 17” racks for just over $1,000. But if you examine closely how most KVMs are used, you’ll discover only a few compelling reasons to justify the expense (and rack space) that a physical KVM imposes. The vast majority of KVM use comes from routine administrative tasks that involve installation, configuration, updates or patches, and management of servers and other devices (such as routers and switches) that can just as easily be enacted using remote access from an administrator’s desktop or notebook PC. The basic concept of a virtual KVM, sometimes abbreviated as VKVM or vKVM, involves using some kind of remote access protocol and related software to establish a connection across the network from one computer to another. Perforce, when making such a connection, a login session is created on the remote computer, where a window on the local (or administrator’s) machine reflects the remote desktop, so that what’s displayed inside that window shows what’s happening on the remote system. Likewise, mouse and keyboard input on the local machine is ferried across the network to the remote machine so that it may be operated, and all responses to such input are then carried the other way back to the local machine to display the ensuing responses and results. Simply put, a vKVM substitutes a PC for a real or physical KVM, and uses the network to create connections that a real or physical KVM might create through a variety of links that also include the network, but might also include serial, USB, VGA or DVI, and other kinds of cables and connections. Why bother with real, physical KVMs? Sometimes, the network goes down, or a server or other device might itself lose network connectivity for a variety of reasons (software bugs, failed network interfaces, protocol stack problems, and so forth). In those situations, remote access disappears along with network access because such access depends entirely upon working network links between local and remote machines. KVMs, on the other hand, usually support sideband or different and direct connections to servers that permit access even when the network is down. In a nutshell, that’s why you can’t simply toss out all your current KVMs and refuse to buy another ever again. But because the vast majority of KVM use occurs when network access is readily available, there’s also no reason to over-spend on KVMs or to insist that administrators use KVMs rather than remote access for tasks that don’t involve troubleshooting network problems of some kind. Remember then, that KVMs keep working even in the face of network trouble, but that vKVMs work most of the time for most routine tasks, and you’ll have no trouble understanding why KVMs must still play a role, but that vKVMs can do most of the lifting, heavy or otherwise, when it comes to routine network maintenance and administration. What kinds of vKVM tools and technologies make sense? For Windows networks, the Remote Desktop Protocol (aka RDP) is included with all Windows Server versions and in all Windows Desktop versions at Professional (Windows® XP and Windows® 7) or Business (Windows® Vista) and better (Ultimate and Enterprise, for both Vista and Windows® 7). Using the built-in Remote Desktop Connection facility, administrators can log onto a Windows server (or desktop) of their choosing and perform nearly everything they can do when attached to the same machine directly or via a KVM. They can also cut and paste content from the local desktop to the remote desktop, and vice-versa, in addition to driving a remote interface locally to their heart’s content. Figure 1: The Windows Remote Desktop Connections lets administrators connect to remote PCs using either computer names or IP addresses. Of course, many organizations use other operating systems besides (or alongside) Windows, so alternatives to RDP and the Remote Desktop Connection facility are needed. There are lots of commercial and freeware or open source products from which prospective users can choose. On the open source side, the SourceForge “open source kvm and console management site” at okvm.sourceforge.net (click the Virtual KVM tab) points to numerous alternatives that work with many different platforms and OSes, including Windows®, MacOS, Linux®, and Unix®. The Wikipedia KVM_switch article includes a section entitled “Software Alternatives” that lists numerous commercial options available to buyers interested in commercial-grade, supported products. And companies such as Citrix®, Symantec™, RealVNC, and many others also offer eminently suitable remote access and control packages that can do the job across multiple platforms as well. In rethinking IT budgets and server room or data center planning, it’s often wiser and cheaper to budget for and include administrator desktop or notebook PCs in lieu of KVMs for routine administrative tasks. That doesn’t mean you can do away with KVMs entirely because they will still prove necessary at some times (when the network is down or unavailable to some specific machine or device) and for some tasks (bringing a new server up from bare metal, or restoring a crashed server from the same state). But for most tasks, and at most times, IT professionals will prefer vKVMs because they can use their own, familiar equipment to perform their most routine and regular tasks. Related Information From Dell.com: Create a Network Roadmap.

KVM stands for “keyboard, video, and monitor” and describes hardware devices that enable IT professionals to interact with, and operate remote devices (servers, mostly) that may lack all of these items. A virtual KVM extends the concept further and uses remote network access so a desktop or notebook PC provides the keyboard, video, and monitor inputs and outputs for network attached devices.

Real KVMs cost money, sometimes substantial sums; virtual KVMs are cheaper, if not free. Savvy CIOs and IT professionals find them useful, functional and affordable.

In most server rooms and in nearly all data centers, KVMs are often built into one or more server racks. These generally take the form of 1U slide out drawers, with pop-up monitors and slide-out keyboards; they also include wireless or wired mice to support pointing and clicking on GUI interfaces as circumstances so often require when installing, configuring, managing, or troubleshooting servers, routers, switches, and other typical computing gear. For example, Dell offers various 1U KVM consoles that incorporate 17” flat screen monitors, keyboards, and touch pads (in lieu of an actual mouse) that integrate directly and easily into standard 17” racks for just over $1,000.

But if you examine closely how most KVMs are used, you’ll discover only a few compelling reasons to justify the expense (and rack space) that a physical KVM imposes. The vast majority of KVM use comes from routine administrative tasks that involve installation, configuration, updates or patches, and management of servers and other devices (such as routers and switches) that can just as easily be enacted using remote access from an administrator’s desktop or notebook PC.

The basic concept of a virtual KVM, sometimes abbreviated as VKVM or vKVM, involves using some kind of remote access protocol and related software to establish a connection across the network from one computer to another. Perforce, when making such a connection, a login session is created on the remote computer, where a window on the local (or administrator’s) machine reflects the remote desktop, so that what’s displayed inside that window shows what’s happening on the remote system.

Likewise, mouse and keyboard input on the local machine is ferried across the network to the remote machine so that it may be operated, and all responses to such input are then carried the other way back to the local machine to display the ensuing responses and results. Simply put, a vKVM substitutes a PC for a real or physical KVM, and uses the network to create connections that a real or physical KVM might create through a variety of links that also include the network, but might also include serial, USB, VGA or DVI, and other kinds of cables and connections.

Why bother with real, physical KVMs?

Sometimes, the network goes down, or a server or other device might itself lose network connectivity for a variety of reasons (software bugs, failed network interfaces, protocol stack problems, and so forth). In those situations, remote access disappears along with network access because such access depends entirely upon working network links between local and remote machines. KVMs, on the other hand, usually support sideband or different and direct connections to servers that permit access even when the network is down.

In a nutshell, that’s why you can’t simply toss out all your current KVMs and refuse to buy another ever again. But because the vast majority of KVM use occurs when network access is readily available, there’s also no reason to over-spend on KVMs or to insist that administrators use KVMs rather than remote access for tasks that don’t involve troubleshooting network problems of some kind. Remember then, that KVMs keep working even in the face of network trouble, but that vKVMs work most of the time for most routine tasks, and you’ll have no trouble understanding why KVMs must still play a role, but that vKVMs can do most of the lifting, heavy or otherwise, when it comes to routine network maintenance and administration.

What kinds of vKVM tools and technologies make sense?

For Windows networks, the Remote Desktop Protocol (aka RDP) is included with all Windows Server versions and in all Windows Desktop versions at Professional (Windows® XP and Windows® 7) or Business (Windows® Vista) and better (Ultimate and Enterprise, for both Vista and Windows® 7). Using the built-in Remote Desktop Connection facility, administrators can log onto a Windows server (or desktop) of their choosing and perform nearly everything they can do when attached to the same machine directly or via a KVM. They can also cut and paste content from the local desktop to the remote desktop, and vice-versa, in addition to driving a remote interface locally to their heart’s content.

Figure 1: The Windows Remote Desktop Connections lets administrators connect to remote PCs using either computer names or IP addresses.

Of course, many organizations use other operating systems besides (or alongside) Windows, so alternatives to RDP and the Remote Desktop Connection facility are needed. There are lots of commercial and freeware or open source products from which prospective users can choose. On the open source side, the SourceForge “open source kvm and console management site” at okvm.sourceforge.net (click the Virtual KVM tab) points to numerous alternatives that work with many different platforms and OSes, including Windows®, MacOS, Linux®, and Unix®. The Wikipedia KVM_switch article includes a section entitled “Software Alternatives” that lists numerous commercial options available to buyers interested in commercial-grade, supported products. And companies such as Citrix®, Symantec™, RealVNC, and many others also offer eminently suitable remote access and control packages that can do the job across multiple platforms as well.

In rethinking IT budgets and server room or data center planning, it’s often wiser and cheaper to budget for and include administrator desktop or notebook PCs in lieu of KVMs for routine administrative tasks. That doesn’t mean you can do away with KVMs entirely because they will still prove necessary at some times (when the network is down or unavailable to some specific machine or device) and for some tasks (bringing a new server up from bare metal, or restoring a crashed server from the same state). But for most tasks, and at most times, IT professionals will prefer vKVMs because they can use their own, familiar equipment to perform their most routine and regular tasks.

Related Information From Dell.com: Create a Network Roadmap.