KVM

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KVM

Postby Marrea » Sun Sep 21, 2008 10:56 am

Hi

Wondered if anyone can recommend a KVM which will work nicely with Linux - in particular with my main distros, SUSE and Ubuntu.

At long last I've decided to replace my trusty Iiyama 19" CRT with a TFT. The Iiyama had dual VGA inputs which was very handy as I could have both my desktops plugged in permanently to the monitor. The fact that I still had to swap the mouse and keyboard over didn't really bother me too much.

However my new TFT (an HP w1907v) has only the one VGA input and I thought it was about time I tidied things up and bought a KVM. But knowing how temperamental Linux can be with some items of hardware, I thought I would check first to see if anyone could recommend a reliable model.

Thanks.
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RE: KVM

Postby ollie » Sun Sep 21, 2008 11:57 am

I use a UNICLASS DVI-202-SK, 2 port DVI USB KVM switch (metal case) with audio, mic, 2x USB2.0 hub and 2 sets of 1.2M cable with Linux (Ubuntu and openSUSE) and Windows XP 64-bit (rarely) and Mac OS X on a G4 PowerMac. I also use a Belkin 4-port USB+PS/2 VGA KVM with openSUSE 10.3, Ubuntu 8.04 Server and Mac OS X 10.4 Server for the past few years.

Pretty much any modern KVM should work, just male sure that all required cables are supplied :wink:
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Postby Marrea » Sun Sep 21, 2008 12:51 pm

Hi ollie

Many thanks for this. I've just been having a look at the Belkin site and I see they specifically mention that their Switch2 KVM can be used with Linux, which is promising. The only slight problem is that they do one model for USB mouse and USB keyboard and another for PS/2 mouse and PS/2 keyboard. Unfortunately all my keyboards are PS/2 and all my mice are USB! However, I am sure this is not insurmountable. A USB to PS/2 adaptor would no doubt do the job.
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Postby ollie » Mon Sep 22, 2008 4:46 am

I've had troubles with USB-PS/2 adaptors with some KVM in the past. That's the reason I ended up with the Uniclass, my Mac G4 only has USB and DVI connectors. It was easier to get a wireless USB Keyboard + Mouse (actually a Microsoft Wireless Multimedia 1.0 :lol: ) and use the USB cables to both Mac and Linux.

The more expensive Belkin KVM have both USB and PS/2, but that's nearly $AUD1000.00 - not really an option :wink:
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Postby Marrea » Mon Sep 22, 2008 8:05 pm

ollie wrote:I've had troubles with USB-PS/2 adaptors with some KVM in the past.

I must admit, before seeing your latest post, I was beginning to think myself that an adaptor might not be a good idea, so I decided to buy a USB keyboard (you can never have too many keyboards kicking around the place!!) and a Belkin KVM USB Switch 2.

First off, I ran into difficulties when installing the KVM because one of the computers wouldn't boot owing to"keyboard error or no keyboard attached". I guessed that was probably something to do with a BIOS setting so I disconnected the KVM, plugged the mouse and keyboard directly into the errant computer, rebooted, had a hunt around the BIOS and found which setting to change. That enabled me to get the gadget recognised by both computers.

However, I'm not particularly impressed with its reliabilty so far. I have spent most of this afternoon trying to get it to work properly - and that's just in Windows for goodness sake. :(

Switching from computer 1 (Windows XP and Fedora 7) to computer 2 (Windows XP plus 8 distros) is fine as regards the monitor but the mouse and keyboard keep freezing. Sometimes a reboot will fix it. Other times I have to unplug the USB cable, wait a few seconds and then plug it in again. That's the USB cable which goes from the Belkin base to the computer I'm talking about, not the USB cable from the mouse itself into the base.

I did actually boot into SUSE 11.0 on computer 2 briefly and monitor, mouse and keyboard seemed fine in that. But I had to break off to go and get my other half's evening meal. :wink:

Just returned now for further fiddling. Up until now I have only been switching from Win XP on one computer to Win XP on the other. I'm now going to try switching from SUSE on computer 1 to Fedora on computer 2 and see if I get the same mouse and keyboard freezing problem. :roll:

ollie wrote:The more expensive Belkin KVM have both USB and PS/2, but that's nearly $AUD1000.00 - not really an option :wink:

No indeed. As you say, not really an option. :lol:
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Postby wyliecoyoteuk » Mon Sep 22, 2008 9:59 pm

Marrea,
I use a Belkin flip KVM, and it works fine with Windows and Linux, but I have noticed that some of the new Xservers (specifically Ubuntu 8.04.1) detect the display at boot time and set the native resolution accordingly, useful if you switch monitors a lot, but...
If the monitor is not connected(and selected by the KVM) at X start up then you may get 640x480 :(

I have had similar shennanigans with windows, which can also insist on re-detecting your mouse and/or keyboard every time you switch.

Annoying, to say the least.


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Postby Marrea » Tue Sep 23, 2008 10:23 am

wyliecoyoteuk wrote:I have had similar shennanigans with windows, which can also insist on re-detecting your mouse and/or keyboard every time you switch.

Annoying, to say the least. :roll:


wyliecoyoteuk

I obviously need to do a lot more testing of this product but I found this morning when I turned on computer 1 (Win XP and Fedora) that I was unable to select Fedora from the boot menu because at that stage the keyboard wasn't recognised. So I had to wait for it to boot into the default o.s., Win XP. The keyboard and mouse were still not recognised. So I removed the usb plug from the computer, waited a few seconds, plugged it back in, and the keyboard and mouse then became active.

It's not going to be much use to me if I can't select individual operating systems from the boot menu, and this business of having to keep taking the usb plug out and plugging it back in again is ridiculous. :?

Still haven't done any proper testing with my Linux distros.
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Postby ollie » Tue Sep 23, 2008 11:33 am

Sorry to hear you're having so much trouble. Windows can be really funny with having keyboard and mouse connected during boot (and afterwards), make sure you have USB Keyboard, Mouse and usually Legacy Devices enabled in the BIOS. If it doesn't work with your systems take it back to the supplier. I also don't tend to re-boot my systems much anymore, having settled on Ubuntu 64-bit and running Windows and other distros within VirtualBox VMs. I switch to my Mac G4 when using my Canon iP4200 printer or doing some graphical web production.

I have supplied and used the Uniclass Desktop KVM - both USB DVI and USB VGA models with very few problems. Their official web site is Uniclass Desktop USB KVM Switches. Hope you can get this sorted.
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Postby Marrea » Tue Sep 23, 2008 4:07 pm

ollie wrote:make sure you have USB Keyboard, Mouse and usually Legacy Devices enabled in the BIOS.


Well I don't know, I'm sure. :?

Computer 1's BIOS has a setting for USB Legacy Support. I can't find anything separate about keyboard and mouse individually. The USB Legacy Support is set to Auto.

The motherboard manual says: "The default of Auto allows the system to detect a USB device at startup. If detected, the USB controller legacy mode is enabled. If not detected, the USB controller mode is disabled. When you set this field to Disabled, the USB controller legacy mode is disabled whether or not you are using a USB device. Configuration options: Disabled, Enabled, Auto."

Computer 2's BIOS similarly has a USB Legacy Support setting, which is set to Auto. Again I can't find any separate settings for keyboard and mouse.

The motherboard manual says: "Setting to Auto allows the system to detect the presence of USB devices at startup. If detected, the USB controller legacy mode is enabled. If no USB device is detected, the legacy USB support is disabled. Configuration options: Disabled, Enabled, Auto."

If I plug the USB keyboard and mouse direct into the computer (and this applies to both of them), the keyboard is active at boot screen. From what the two motherboard manuals say, this is what I would expect.

Using the Belkin Switch 2, at first boot of the day (and this applies to both of the computers) the keyboard is not active and therefore I can't select anything from the boot menu but just have to wait for the default o.s. to start up. To get the keyboard and mouse working, I then have to remove the Belkin's USB cable from the computer, wait a few seconds and plug it back in.

However, once the keyboard and mouse are working, if I then reboot (and again this applies to both computers) the keyboard is active and I can then select items from the boot menu.

So, not using the Belkin Switch, the keyboard is recognised at boot. Using the Switch, it's not.
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Postby wyliecoyoteuk » Tue Sep 23, 2008 7:10 pm

It will only be detected if that pc is selected when it is switched on.
Do you totally power down your PC? (unplug/switch off at mains) that will stop it being detected too.
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Postby towy71 » Tue Sep 23, 2008 7:24 pm

Have tried the "hot key" change? I have two older ps2 machines, that my befuddled state gets confused, :D hitting Scroll Lock twice changes to either of the two :D
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Postby Marrea » Tue Sep 23, 2008 7:32 pm

wyliecoyoteuk wrote:It will only be detected if that pc is selected when it is switched on.

The Belkin remote, which is the switching control, has an LED which indicates with a yellow or green light which PC you are currently switched to. This morning I turned on computer 1 (yellow) and the yellow light was showing, so I assumed that PC was being selected.

Do you totally power down your PC? (unplug/switch off at mains) that will stop it being detected too.

Yes, I always switch off at the mains in the evening. So are you saying that by doing this, my keyboard and mouse will never be detected at first boot of the day while I am using the Belkin switch, even though they are detected if plugged directly into the computer? Should I try leaving the mains switch turned on overnight and see what happens?
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Postby Marrea » Tue Sep 23, 2008 7:39 pm

towy71 wrote:Have tried the "hot key" change? I have two older ps2 machines, that my befuddled state gets confused, :D hitting Scroll Lock twice changes to either of the two :D


Hi towy

I believe there is downloadable software on the Belkin site for the USB version of the Switch 2 - the one I have - which enables you to use the keyboard (instead of the remote) to change from one computer to another. However, I don't have any problems using the remote to switch from one machine to another, once I have initially managed to get the mouse and keyboard up and running after first boot by unplugging and replugging the Belkin's cable. It's that initial recognition that is causing me grief. :?
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Postby wyliecoyoteuk » Tue Sep 23, 2008 8:17 pm

Marrea wrote:
wyliecoyoteuk wrote:It will only be detected if that pc is selected when it is switched on.

The Belkin remote, which is the switching control, has an LED which indicates with a yellow or green light which PC you are currently switched to. This morning I turned on computer 1 (yellow) and the yellow light was showing, so I assumed that PC was being selected.


Mine is the same, the yellow light is the default and it won't switch to the green unless there is a video signal on that side.


Do you totally power down your PC? (unplug/switch off at mains) that will stop it being detected too.
Yes, I always switch off at the mains in the evening. So are you saying that by doing this, my keyboard and mouse will never be detected at first boot of the day while I am using the Belkin switch, even though they are detected if plugged directly into the computer? Should I try leaving the mains switch turned on overnight and see what happens?


Not sure, but mine works OK, and I leave mine shutdown, but not totally powered off.
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Postby Ram » Wed Sep 24, 2008 1:54 pm

Marrea,

Try setting the BIOS options for legacy from Auto to Enabled.

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