Date: Mon, 12 Sep 2011 21:20:58 +0200 From: Polytropon <freebsd@edvax.de> To: David Brodbeck <gull@gull.us> Cc: FreeBSD <freebsd-questions@freebsd.org> Subject: Re: KVM switch with FreeBSD-8.2 Message-ID: <20110912212058.300af40c.freebsd@edvax.de> In-Reply-To: <CAHhngE1008-s9vPjJSU70pn4bpgDwvzPpas1YH8UKmuq5K2DHQ@mail.gmail.com> References: <BLU0-SMTP69E96B700AEF3C73A953C93030@phx.gbl> <20076.56940.849206.283586@jerusalem.litteratus.org> <Pine.GSO.4.64.1109111422260.21301@nber6> <BLU0-SMTP46734401C83EFD3F6AAB72293030@phx.gbl> <alpine.LFD.2.00.1109111619480.4016@nber7.nber.org> <alpine.BSF.2.00.1109111438330.10961@wonkity.com> <20110912014355.19f3efa6.freebsd@edvax.de> <CAHhngE1008-s9vPjJSU70pn4bpgDwvzPpas1YH8UKmuq5K2DHQ@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 12 Sep 2011 10:45:59 -0700, David Brodbeck wrote: > On Sun, Sep 11, 2011 at 4:43 PM, Polytropon <freebsd@edvax.de> wrote: > > On Sun, 11 Sep 2011 15:10:48 -0600 (MDT), Warren Block wrote: > >> On Sun, 11 Sep 2011, Daniel Feenberg wrote: > >> > >> > If you are asking, "Is there a FreeBSD command to cause the KVM switch to > >> > move to the next system?" then the answer is "I don't know and it would amaze > >> > me if there were." > >> > >> There's often a key sequence to advance to the next port or a specific > >> port. > > > > That can _sometimes_ be a problem when the KVM switch > > doesn't properly detect this sequence - or maybe the > > user has already defined that sequence for some action > > in X, so X "catches" the sequence and acts properly. > > X "catching" the sequence won't stop the switch from reacting to it -- > it's done in hardware in the switch. But of course X may do something > undesirable if the switch passes the key combination through. Yes, I thought of something like that _might_ happen, depending on the firmware of the KVM switch. You know, keys that are useful to users may be a first-class candidate for the manufacturer to say: "Oh look, nobody uses *that* key, let's hardcode it as switching key!" :-) > The two most common ones are Ctrl, Alt, Shift (rapidly in sequence) > followed by a port number, or Ctrl twice. The latter can be a little > too easy to trigger accidentally. Fully agree, that's not very well thought... but maybe the product designers primarily orient at the "Windows" main target group that hardly uses the keyboard. :-) > The USB switches generally emulate a generic USB keyboard and mouse, > so drivers aren't a problem. Sometimes they work by simulating a USB > disconnect from the machine they're switching to, though, so you need > good keyboard and mouse hotplug support in the OS. FreeBSD's devd should handle that fine. Also the absense of a keyboard at system startup shouldn't matter. > Generally these switches don't react well to having anything but a > keyboard in the keyboard port and a mouse in the mouse port. If you > have a hub built into your keyboard the hub will be useless when > you're using one of these switches. Uh, that can be a problem when using professional desktop equipment, e. g. a Sun keyboard where you can connect the mouse directly to the keyboard (a feature known from the Apple ADB configurations of the 80's, if I remember correct- ly, but Sun also had this functionality in the pre-USB era; it's also a feature returning in Apple's modern USB products to attach the short-wired mouse to the keyboard's USB hub). I furthermore assume using the keyboard's hub for attaching other USB devices (memory sticks, MP3 players or cameras) to the keyboard's hub is a no-go then. Regarding the possible problem with monitors: As an example, the Nvidia documentation (HTML version located at /usr/local/share/doc/NVIDIA_GLX-1.0/html/) contains this interesting option: Option "ConnectedMonitor" "string" Allows you to override what the NVIDIA kernel module detects is connected to your graphics card. This may be useful, for example, if you use a KVM (keyboard, video, mouse) switch and you are switched away when X is started. In such a situation, the NVIDIA kernel module cannot detect which display devices are connected, and the NVIDIA X driver assumes you have a single CRT. Something similar _may_ be useful in case of too much malfunctioning autodetection magic. :-) -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110912212058.300af40c.freebsd>