IT directors, network administrators, and storage professionals often complain about "server sprawl" — the scattering of servers across distributed computing environments. A convenient way to deal with server sprawl is to deploy KVM (keyboard, video, mouse) technology. KVM devices allow administrators to manage multiple servers from a single user interface (or set of linked interfaces).
Open Paths To Server Service
Essentially, a KVM device is a switch that allows multiple servers to be connected to a single keyboard, (video) monitor, and mouse. From that interface, administrators can perform server maintenance tasks on any of the servers connected to the switch. Says Herman Chan, director of product management for KVM vendor Raritan Computer, Inc. (Somerset, NJ), "KVM's fundamental capability is emulation — the ability to spoof the server into thinking there is a keyboard, monitor, and mouse attached to it."
Access through KVM switches enables a range of server management tasks. According to John Cooper, CEO of KVM vendor Avocent (Huntsville, AL), "IT administrators can do upgrades, set policies on usage, and control access to particular servers in a server farm or data center."
Unlike server management software, which tends to be loaded separately onto each box, a KVM switch doesn't require the server's operating system to be up-and-running for users to perform maintenance tasks. That's because, instead of being connected to a network port on the server, which establishes an in-band connection, the switch is connected to a serial (or KVM) port, creating an out-of-band connection. As a result, administrators have BIOS (basic input/output system)-level access to the server. Says Raritan's Chan, "KVM switches allow you to make hardware or firmware changes on the server even before the software reboots."
One Viewpoint, Thousands Of Server Views
In the most basic of KVM deployments, the single user interface is part of an office workstation, with a two-port KVM switch connecting the monitor to two PCs. In most scenarios, however, the interface is an administrative console in a data center. In a small data center, a single console connected to an 8-port unit may suffice. In large enterprises, with extensive server sprawl to rein in, port counts can scale tremendously. "At the very high end of KVM — for instance, a 16-user by 64-channel enterprise-class model — several units can be strung together to support up to 64 users and up to 10,000 servers," says Chan. Avocent's Cooper concurs on the scale of large KVM rollouts: "Depending on authorization and access control, one network administrator could take control of thousands of servers from one screen." In multiswitch, multiconsole environments, advanced KVM devices enable multiple users to simultaneously access the same server.
The KVM Road Show
In small, single-location data centers, KVM switches still commonly connect servers to consoles over the existing twisted pair cabling used to create the Ethernet network. With CAT 5 (category 5) cabling, the distance between a user and a server can extend to 1,000 feet. But, many companies, particularly those in the large enterprise space, have several server rooms across a campus environment or, increasingly, across multiple remote locations.
The solution? KVM using the Internet. With the advent of Web-enabled KVM technologies, the interface connecting the user through a KVM switch to a server could just as well be a laptop or PDA (personal digital assistant) as a desktop PC or data center console. As David Rahvar, general partner for KVM vendor Rose Electronics (Houston), puts it, "Server access is no longer limited to local workstations. Remote KVM access over the Internet allows additional administrative interfaces to be distributed throughout an entire worldwide organization." As Avocent's Cooper sees it, the addition of digital transmission to KVM's traditional analog process reflects the rapid growth of the corporate server infrastructure. "The trend is clearly toward larger data centers and more server rooms across the company," he says. "That trend pushes the demand for remote access from systems administrators, who can't be constantly traveling to different sites to manage servers." Included in KVM products available today are switches that handle both analog and digital communications.
According to Mike Chen, senior product manager for KVM vendor Belkin Corp. (Compton, CA), there are two ways Internet-based solutions gain access to remote servers. One uses proprietary remote access software to call up the KVM switch. However, this method requires that the software be installed on each remote console. "The more popular way is through a standard Web browser," says Chen. "That allows the systems administrator to access the KVM unit — regardless of what platform it runs on — as long as there is an Internet connection." Of course, carrying out server management tasks over the public Internet brings with it concerns about security. But, Chen confirms that manufacturers of Web-based KVM switches build security into their devices.
Obviously, Web-based KVM solutions offer the greatest potential for companies to reap the benefits of more efficient management. Nonetheless, even modest KVM configurations — for example, an eight-port version — can have impact. The more servers an administrator can monitor and manage from the same workstation, the less time that key IT person is tied up crossing the floor, heading down the hall, calling a remote location, or getting on a plane. And, those time-saving measures give the company more of what its IT team is entrusted to provide: uptime.