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KVM Switches FAQ

KVM Switches FAQ – What you need to know.

KVM switches come in different sizes and can be used in a variety of environments. Applications range widely-a simple KVM switch with a few ports can permit an administrator to manage several servers, while an integrated KVM switching system can provide hundreds of administrators KVM, console, and remote power control of thousands of servers.

Below are answers to frequently asked questions about KVM switches:

Installation and Set Up

1. How much rack space does a KVM switch require?

Depending on the size of the KVM configuration, for up to a 42-port solution, most KVM switches typically occupy 1U of rack space. Once you upgrade to a 64-port KVM solution, 2U of rack space will likely be required.

2. How difficult is it to install and set up KVM switches?

Most KVM switches are fairly easy to set up and feature “plug and play” functionality. The more cumbersome piece of this process is that each of the systems attached to the KVM switch may require a restart, depending on their peripheral connections.

3. Will the KVM switch I am considering be compatible with other KVM switches I already have?

Although most KVM switches can be daisy-chained for port expansion, users must consider possible compatibility issues when different manufacturers’ devices are used together.

4. What cabling options can be used with a KVM switch?

In smaller applications with ample cable space, coax 3-1 cables may fit the bill. Large installations will most likely require KVM switches that allow users to implement point-to-point UTP cabling.

5. Are there any other costs related to KVM switch solutions?

Users should remember to order rack mount accessories such as rack mount kits, interface cables, or additional warranties at the time of the KVM switch purchase. Often, accessories are not bundled with the KVM solution.

6. What bandwidth is required for remote IP access?

Most compression technologies use differentials, sending only the changes that appear on a screen to update the user screen. However, your bandwidth requirements will vary significantly depending on the graphic intensity of the application you are using.

KVM Switches FAQ

Expansion and Replacement

1. After installation, can I expand the solution?

Expanding the number of systems supported by a KVM installation is relatively easy. For example, the Raritan Paragon II 8-user, 32-port solution offer users an option to add 32 ports by adding the Raritan P2-UMT832S stacking model to the main Paragon II 8×32 matrix switch with a 6-inch SCSI cable, so that it becomes an 8X64 architecture instead of an 8X58.

2. Can I easily add local user stations in a datacenter?

Yes. However, it is important to select a switch that will provide room to grow. If a KVM switch is not maximized at the user level, adding more users is as simple as connecting additional user stations with point-to-point UTP. Keep in mind that each analog KVM switch has a finite number of users; digital KVM switches allow more room for expansion.

3. What is the degree of difficulty in replacing switching equipment?

Replacing equipment is usually easy, as replacement dongles or KVM switches have “Plug-and-play” functionality.

Features of KVM Switches

1. Do KVM switches allow users to automatically cycle/scan video on all connected ports?

A “port scan” feature is often included with most, if not all, models of KVM switches. A simple hot-key command will permit users to view a selected list or all ports attached to the KVM switch and show the video of each for a selected amount of time.

2. What naming options do KVM switches offer?

KVM switches limit the amount of characters used to name servers through the OSD. Some OSD menu systems allow users to implement alpha and/or numeric naming conventions.

3. What is the resolution and performance over IP?

Resolutions vary by device, and some provide a maximum of up to 1600X1200 at 60Hz over IP. If you have high resolution requirements, consider analog KVM switches, as they provide a higher resolution than digital KVM switches.

Supported Features, Devices, and Platforms

1. Do KVM switches support serial devices (i.e., routers, headless Unix, etc.)?

Yes. Some high-end KVM enterprise solutions provide support for serial devices. Avocent and Raritan devices provide support for serial devices through the use of dongles, and Rose Electronics’ devices provide serial support at the switch level and can support these devices through coax cables.

2. Can all types of devices (Sun, USB, AIX, SGI, RS6000, HP9000, DEC, MAC, chained IBM 330 servers, serial/TTY, etc) connect directly to a KVM switch?

Yes. Interface modules allow flexibility. All that is needed is the proper serial computer interface module or dongle with the right connections. Again, if a dongle is not available, an adapter such as a Raritan AUATC adapter, can be used to convert all serial connections to a standard PS2 keyboard and VGA monitor connection.

3. What client platforms does KVM over IP support?

Platform support varies by device. For example, Raritan offers a Java-based multi-platform client and will work with a wide variety of operating systems including Linux, Sun/Solaris, and Macintosh. Other devices use an Active-X platform and provide support only for Windows.

4. Can Sun users use their native Sun keyboard, mouse, and display?

Yes, some high-end products allow users to plug Sun peripherals into console ports. In addition, along with native Sun connections, users also have the choice between USB, and PS2 keyboard/mouse with VGA video.

5. Do KVM switches support audio?

Yes, some products provide audio support. For example, the Rose Electronics UltraView Pro series will support audio for users and computers. In addition, Avocent AMX devices provide multi-user switches that support audio functionality throughout.

6. Do KVM switches support video or video/keyboard sharing? Can multiple users share access to the same computer?

Yes. As long as Port Sharing is set to active across the switch, users will be permitted to share computer ports. However, keyboard and mouse access for editing and management is restricted to only one user at a time. Also, all users connected to the same target computer will view the same video feed.

Remote Power Management

1. Can KVM Switches integrate remote power management functionality?

Yes, integrating a remote reboot device allows administrators to cycle power to a server from a user station or using an internet browser from any location worldwide. Integrated power management solutions allow users to control KVM switching and remote reboot management from the same user interface.

2. Are 3-Phase and 208 power supported?

Yes. Enterprise-level solutions such as Server Technology’s line of remote power management products, provide multiple options for 3-phase or 208 power.

Server Dongles

1. Is there a KVM switch that has the ability to split KVM signals from a single server and send them to two destinations?

Yes. Both the Raritan Paragon II and the Avocent AMX offers a dual-headed dongle for this purpose. This dongle permit users to have dual access into a single server from two separate matrix switching units. This type of dongle doubles the maximum user density for an installation.

2. Do UTP-based KVM dongles offer servers “stay alive” or “keep-alive” functionality?

Yes. A KVM dongle is an active device that pulls power and provides keyboard and mouse emulation. Once the dongle connection is made and the server is started from a cold boot, the dongle is not required to have a UTP cable connected back to the Cat5 KVM switch. A UTP based KVM switch does not need to remain connected to the target systems in order for the computers to operate correctly.

3. Can dongles retain server name information?

Yes. No matter how long a dongle remains dormant, information will carry on when users move or upgrade computers.

Security and Access Rights

1. What levels of access rights/security levels are available?

Enterprise-level devices, for example Avocent’s Mergpoint Unity devices, provide administrators with complete control of all devices attached to the solution. Administrators can then set permissions for all other users. Access rights are usually set at the port level by using advanced features within the OSD of the KVM switch or through management software.

2. How user-friendly is the application to configure user and server rights and profiles?

On most devices, administrators simply point and click their way though the advanced OSD to create user profiles and assign access privileges for all users. The top enterprise offerings include a GUI software for this purpose.

3. Does a KVM’s security features allow you to hide servers/devices from users who don’t have sufficient access rights?

Yes. This feature is set through the “permissions and profiles” feature, and it is available on most enterprise-level Cat5 based, digital KVM switches, and analog KVM switches.

4. Does viewing multiple servers or devices create “blocking”, which doesn’t allow other users to work with those servers?

Blocking can be a problem when KVM switches are stacked or daisy-chained together. Daisy-chained switches leave users with a limited number of pathways to the upper-tier host computers. When all pathways are occupied, users will be blocked out of the remaining systems in the KVM architecture.

5. Do KVM manufacturers have realistic “non-blocked” remote access solutions for smaller remote sites?

Yes. Multiple manufacturers have 1X1 devices that allow for a non-blocked architecture. Depending on the size of this type of installation, you may want to aggregate these 1X1 devices through a centralized management appliance.

6. Do KVM switches offer a “Time Out” feature?

Advanced OSD features on many devices, including the Raritan Paragon II and the Avocent AMX series, for example, will allow administrators to set an automatic time-out feature to log out inactive users that are logged into the KVM system.

7. Can you back up the configuration/user rights database?

Back-up databases can be replicated for the Avocent DSR KVM-over-IP switch. The Hub and Spoke DSView databases can be replicated up to 15 times for fail-safe redundancy.

Read the Top 10 Considerations When Selecting a KVM Switch

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