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The Peculiarly Quiet Decline and Fall of the KVM
- deleted 9y ago[deleted]
- Kurtz79 9y agoPSA: It's about this "KVM": https://en.wikipedia.org/wiki/KVM_switch https://en.wikipedia.org/wiki/KVM_switch Not this: https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine
- noncoml 9y agoThanks! I was wondering why none of the comments made sense.
- StreamBright 9y agoI opened the link because I was wondering what is it talking about when KVM (the virtual machine) is more popular today than ever. :)
- bonzini 9y agoGreat, so there won't be confusion anymore! :)
- plq 9y ago... which makes this a total non-story in my opinion :) Of course KVM switches will eventually disappear; when was the last time any of us (minus datacenter staff) has been to the server room since the dawn of the PaaS age?
- dboreham 9y agoI could never understand why the makers of KVM the virtual machine thing didn't realize they had overloaded an acronym. It isn't as if they weren't likely to have come across KVMs in their work. Were they non-native-English speakers perhaps?
- drzaiusapelord 9y agoSoftware devs aren't sysadmins, I imagine most of the people involved here never have been responsible for actual production physical servers before and never had to use one.
- dboreham 9y agoWeb front end developers sure. Kernel hackers though??
- mark-r 9y agoThe title of the post should be modified to say "KVM switch".
- kindfellow92 9y agoSynergy (https://symless.com/synergy https://symless.com/synergy) may have had something to do with it.
- Quequau 9y agoYeah, I can see how it might not work for everyone but for my needs it's pretty well suited and become part of my everyday workflow.
- jsight 9y agoYep, that is what I use for the same usecase. There is really very little point to a hardware KVM at this point.
- mark-r 9y agoThe remaining use case is when you want to share a monitor along with the keyboard and mouse.
- zedzedb5 9y agoI cannot live without this software. I'm using it to control several computers with a wall of screens. My T460p is the server.
- matthewaveryusa 9y agoFYI synergy is free and oss[1] but I would still recommend paying for it because it's priced fairly and I want to support the development behind it. I think synergy is text-book "how to make money with oss." [1] https://github.com/symless/synergy-core https://github.com/symless/synergy-core
- eigenrick 9y agoI, too, tried in vain to buy a decent quality 4k KVM. Oddly the video worked better than the USB mouse/keyboard. (?) Having failed the KVM route, I, too became a Synergy fan. I don't think Synergy caused the decline of KVM, but it synergy's success is certainly correlated. :)
- keypusher 9y agoThe rise of more powerful graphics cards with the ports and ability to run multiple monitors made this something that ever fewer desktop users need that did before. You can still get good KVMs in the enterprise/hardware market, they are common in server rooms, but even then less so than the old days as most firmware allows remote management.
- blauditore 9y agoI don't understand what this has to do with graphics cards. One is about connecting multiple monitors to one computer, the other about connection one monitor to multiple computers.
- bitL 9y agoFor example, my 3 monitors each have 4 different inputs. My GPUs have at least 3 outputs. So you can connect each GPU to each monitor, then you need a way to switch between different computers at once or separately.
- xg15 9y agoI'd guess the comment about HDCP is onto something. To build a KVM switch that works with modern displays without weird errors, it probably has to be an active HDMI/HDCP endpoint on its own - which means a vendor would either need to get its own sets of keys and do additional work to enforce all DRM restrictions - or they'd have to use leaked keys and prepare to get sued in an instant. Even without HDCP, I remember another article explaining that it's already difficult enough to get two arbitrary HDMI devices to talk to each other because HDMI allows so many different modes of operation. I imagine the situation would get even worse if you had to negotiate common protocols for three endpoints at the same time.
- beojan 9y agoWhat if it physically unplugged the HDMI connection, and reconnected it to the other device? It wouldn't be quite as seamless since the initialization process would be repeated, but it would work.
- blauditore 9y agoNot even physically, but just redirecting the raw signal to another device should work. Maybe artificially break it for a second or so to better simulate plugging out and back in. I can't see how the actual endpoints could tell a difference between that and manually un- and re-plugging into a different device.
- beojan 9y agoThat's what I meant. Electrically, it's identically to unplugging from one device and plugging into the other.
- ztjio 9y agoThis is doable but unappealing as the OS will see the display is gone, and relayout the desktop environment every time you switch. Depending on your OS, and your personal concerns about all your environment behaviors, you might not care. I know I would be very annoyed by this.
- 9y ago
- xiconfjs 9y agoWe are still using it in our testing environment - 8+ servers. We do a lot of pre-OS tests so KVM is the optimal solution - faster and more reliable than IPMI/etc.
- daemin 9y agoThe main thing that has pissed me off with technologies like DisplayPort and HDMI is that I cannot actually turn my monitors off when I'm not using my computer. With DVI I could turn the monitors off and the desktop and applications would stay where they were. With HDMI/Displayport it considers the monitor disconnected, hence re-adjusts the desktop and moves everything around. I would love an option that I could switch on and it would "disable HDCP" on these monitors so they could function like they did before. Sure I couldn't play some videos but that's not a great loss for me.
- paol 9y agoYou must have some dodgy hardware. This is definitely not normal, at least with HDMI. I just tried it with the monitor right in front of me, even unplugging it from the wall didn't cause the laptop to drop the monitor like it would if I had disconnected the HDMI cable.
- 88 9y agoSounds perfectly normal to me. I’ve only ever seen the behavior daemin describes.
- exikyut 9y agoSee my reply to the subthread commentor.
- daemin 9y agoWhat I had learnt from investigating this issue is: * It's been a problem since at least 2012 * HDMI cables have an active-low connection pin, therefore it's easier to fool the video card into thinking the monitor is still connected. * DisplayPort is an active-high signal, therefore if the monitor powers off, it's the same thing as the cable being physically disconnected. Ideally I would be able to switch the monitor off in such a way that it still maintains a connection, just that the display is off. Edit: formatting
- 9y ago
- reacweb 9y agoI think the use cases are disappearing. Using a KVM means working near many noisy computers. I do not know the location of most of the machines I am using remotely from my dumb windows PC. Poor guys that must use a KVM.
- blibble 9y agoI use two machines as part of normal operation, my monitors have multiple inputs which can be switched with one button and with synergy the mouse/keyboard can move across no need for a KVM
- chha 9y agoThis! I was a big user of KVMs for many years, but haven't used one for the past ten(ish) years after discovering Synergy. I don't switch monitor inputs, but have had a bunch of them connected to various computers, and being able to switch with no effort at all is great.
- AdrianRossouw 9y agoI use this one for my 40" 4k monitor, and it works great : https://www.amazon.com/gp/product/B01BSNSOPU/ https://www.amazon.com/gp/product/B01BSNSOPU/
- petecox 9y agoOh boy, the price! The article is lamenting the expense of 'modern' KVM switches. For reference, a switch with 'legacy' USB 2.0/VGA connectors that powers my ageing home PCs is this model: https://www.ebay.com.au/itm/All-in-one-Mini-2-Ports-KVM-Manual-Switch-Box-Adapter-w-USB-Connector-L4X3/322418050131 https://www.ebay.com.au/itm/All-in-one-Mini-2-Ports-KVM-Manu...
- topspin 9y agoThat's the second endorsement of an IOGEAR DisplayPort solution I've seen so far. The full product line is here: https://www.iogear.com/solutions/kvm https://www.iogear.com/solutions/kvm $480 to solve the dual head 4K DisplayPort problem, and it works, apparently. Now, is that a reasonable price? I have to say I think so. This is not a trivial problem and this equipment isn't being manufactured by a dozen companies and flying off Best Buy shelves. Given the low demand and difficult requirements I think the price is reasonable. If your use case involves smoothly switching between 2-4 high resolution dual head systems $480-$680 probably amounts to something in the range of 5-20% of the cost of the entire system. I don't buy the argument that this cost makes such a KVM pointless because one can simply buy more display(s) and input devices instead: that takes a lot of space and results in a lot of underutilized hardware.
- anoother 9y agoWendell, from the YouTube channel Level1techs, has worked with a Chinese(?) OEM on custom firmware for Displayport KVMs and is selling them: https://twitter.com/tekwendell/status/933441036138971137?s=17 https://twitter.com/tekwendell/status/933441036138971137?s=1... Still more expensive than a 4k monitor, but heading in the right direction.
- oeuviz 9y agoIronically, to me personally KVM [1] is reason #1 for not owning and using the other KVM [2]. I simply do not need an additional physical machine as what I need is available in a VM at no cost with plenty of performance. [1] https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine [2] https://en.wikipedia.org/wiki/KVM_switch https://en.wikipedia.org/wiki/KVM_switch
- snarfy 9y agoAll of our meeting rooms have computers with KVMs in case someone wants to use their laptop on the big screen. Or they can just remote in. It's kind of dumb.
- sdfjkl 9y agoKVM switches used to be a huge and super important (and expensive) thing in rack server farms back when every rack or every few racks had a pull-out tray with a keyboard and a monitor. Technology moved on. First the tray and monitor disappeared with KVM-over-IP, which saved many trips to the server room. Then the KVM switches themselves disappeared, as manufacturers integrated out-of-band remote access into the servers, first with add-on boards, then onboard and finally on-chip (this is what Intel AMT does, when it isn't busy running rootkits). The little two-PC switch box the article refers to (I think) was always a spillover from the server KVM technology, except with a very small market and more difficult to make. Servers don't need sound and are fine with just VGA video. Home computers want USB (which variety?) and audio switched, or high bandwidth signals that are very touchy about interference or suddenly being connected to a different device like HDMI, Displayport or Thunderbolt. And then people want the stuff for cheap. > signal switches with arbitrary bandwidth remain available: analogue relays Have you tried that? Cut a HDMI cable in half and splay it out, then try switching that to another display. See what happens. If it were that easy, it'd be around (or you'd just be building it yourself).
- fraqed 9y agoAs well the use of KVMs by PC enthusiasts has most likely been replaced by virtual machines.
- OliverJones 9y agoYes, no doubt that rack-based kvm stuff disappeared. It was awful: hard to rig, hard to use with confidence. (Confidence? "Wait, wait, am I talking to data2 or web4 or what?) KVM was a just-barely-competent solution to a hair-on-fire (=== must-solve-now) problem.
- NameOpenSource 9y ago"What ? this was the production server ?... woops"
- gambiting 9y agoThe easiest solution is to just buy an HDMI switch(there's loads of them, even ones which work with 4K signal, and they don't disrupt DHCP) and a USB switch. Total solution should fit in about 40-50 dollars.
- frou_dh 9y agoThe ones that used VGA ports for video often used to degrade the image quality in comparison to a direct connection. Frankly there are entire categories of desktop computer peripherals that get a deserved reputation for being flakey junk. USB hubs used to be this way, but presumably they've finally got those right. Inkjet printers too.
- al2o3cr 9y agoUSB hubs used to be this way, but presumably they've finally got those right. Not necessarily. I purchased a 10-port hub just a couple years back that was internally three 4-port hubs chained serially. The OSX USB stack couldn't see devices connected to the last four ports...
- cesarb 9y agoWith VGA, it was simple: duplicate the EDID to both inputs, switch the output wires, done. AFAIK, with DisplayPort it's not so simple, since there is a negotiation between the computer and the display, including link training (see https://lwn.net/Articles/736011/ https://lwn.net/Articles/736011/ for instance). IIRC, HDMI also has some bidirectional communication. To work well, a KVM would have to act as a display to the computers, and as a computer to the display, instead of just passively switching some wires.
- petecox 9y agoI bought a USB2.0/VGA switch online for < $10. I had a number of vga and USB type B (aka printer) cables lying in boxes that are now put to good use! A windows laptop and a linux NUC, 5 USB peripherals shared. 4K and all digital HDMI might spell the death of it but I'd be needing new PC(s) to drive such a display in any case.
- arka2147483647 9y agoI think it's a two pronged demise * Current display (DP, HDMP) and peripheral(USB) technology is complex, and probably is going to be expensive to switch in the fly without being unreliable. * Virtual Machines and Remote Desktop solutions are good enough. Sure they can be a bit laggy sometimes, but good enough for most tasks. So i guess that KVM switches are going to be more expensive to make, and there are less customers who really need them...
- z3t4 9y agoOne interesting use-case is having virtual machines with dedicated ports.
- bitL 9y agoI replaced them with standalone USB & HDMI switches. I connect 5 PCs on my desk (main PC, Deep Learning rig, NAS, 2x NUC) first to two 4-port USB switches, then have one 2-port switch that switches between these two 4-port switches, and then a large HDMI switch. It works fine; each of those switches was <$5.
- deleted 9y ago[deleted]
- hyperfekt 9y agoAs far as I am aware from the last time I tried to find such a thing the packet-based interactive nature of modern display standards prevents the cheap implementation of these devices, as opposed to the non-interactive, older standards.
- huevo5050 9y agoThere is a project to build an open source KVM-over-IP Rapsberry pi based. rasky: https://www.nexlab.net/product/rasky/ https://www.nexlab.net/product/rasky/ I have contributed to it but a lot of time without news. Maybe contribute to rasky was risky.
- hudibras 9y agoWhen I worked in the Pentagon, everybody in our office had these to switch between the classified and unclassified computer systems. It was amusing when someone in our large cubicle farm would say, "Hey, check out this email that just came in on the low side," and then two dozen index fingers would reach out and two dozen monitors would blink over to the Windows login screen simultaneously.
- erikbye 9y agoG-man here (not the U.S.). Switching between four systems daily. Scroll Lock x2 + n.
- tmdk 9y agoI think this is because people perceive multiple monitors as giving a better overview, regardless of switches being available at a lower cost, which has caused the market for switches to become a niche market.
- JustSomeNobody 9y agoYou can get a USB switch and a 4K HDMI switch for about $40. I don't currently have a 4K HDMI switch, but my HD switch works just fine. Sure you have two buttons to push (USB and HDMI), but it works and it's cheap.
- cormman 9y agoYep, I got this for my 4k monitor: https://www.amazon.com/gp/product/B071CJWSPF/ https://www.amazon.com/gp/product/B071CJWSPF/ And this for my usb stuff: https://www.amazon.com/Plugable-One-Button-Swapping-Between-Computers/dp/B006Z0Q2SI/ https://www.amazon.com/Plugable-One-Button-Swapping-Between-... It's under $25 total and both work perfectly well.
- python-guy-vt 9y agoThis tone of this article is pretentious and just plain douchey. The author is largely assuming that their small niche (and petty) use case is what everyone who uses a KVM would want (i.e. using a 4k monitor). The single largest use for KVM is for servers, who the hell is wasting money on a 4k monitor for their servers? There are plenty of reliable and affordable KVM's that the author deems as old relics that work just fine for the large majority of consumers.
- npsimons 9y ago> This tone of this article is pretentious and just plain douchey. I got that same feeling. First a "What?! KVMs are no longer sold at all?!" followed by "wait, no, he's lying - KVMs are still sold, they just don't meet his standards." It's clickbait.
- wastedhours 9y agoI still would like a personal one, I get to work from home frequently, and have a personal desktop, personal laptop and work laptop that'd be great to switch between without having to keep changing plugs (as it is, I velcro the HDMI, mouse, keyboard and speaker jack together to keep it easy to handle).
- AdmiralAsshat 9y agoThese days, I believe the monitor is becoming the KVM. High-end Dell laptops have multiple inputs as well as USB slots for peripherals, and even a handful of USB type B to send back downstream. Mine doesn't, unfortunately, so for my two computers plugged into my Dell monitor, I have the keyboard and mouse plugged into a cheap USB switch, while simply cycling through the inputs on the monitor. It's two clicks instead of one with a traditional KVM, but I don't have $150 to blow on a KVM that has something better than a VGA slot...
- dekhn 9y agoI am so happy I don't use KVMs any more. Instead, monitors with multiple inputs, and a simple USB switch for the keyboard.Then I don't have to spend $200 when I upgrade monitors, just so I can switch whatever new resolution I moved to.
- topspin 9y agoI've looked into doing this as well. Have you found monitors that a.) switch inputs without many seconds of delay b.) switch using keyboard input as opposed to banging on balky switches on two displays? My expectation is one button and no delay, not switching the input devices and then switch two monitors one after the other, because I expect to switch frequently. Also, the buttons on a lot of monitors aren't really intended to be used terribly hard; they wear out. Maybe capacitive buttons solve this, I guess, but those can be flaky as well for other reasons.
- dekhn 9y agono, unfortunately all the monitors I use are slow (3-5 seconds) and the keyboard switch takes 2-3 seconds.
- linsomniac 9y agoThis URL starts off with the condition that the KVM needs to be less expensive than adding another display and keyboard, and operate at 4K. So this is targeted towards the home environment? I'd guess that RDP/VNC and the like have pretty much done away with the KVM in that environment.
- k__ 9y agoHaha, those were the days! I had one for my dual desktop setup back in the days. Had a Windows and a Linux machine, but was too poor for second mouse/keyboard/monitor. The Linux machine was some old PC I built from spare parts. I already had a switch that let me change the PC via ctrl+esc on the keyboard. At my first job as a PC technician we still had the old ones with physical switches.
- skriticos2 9y agoThis does not surprise me at all. I have a 4k screen and just thinking about all the fiddly bits between HDMI, HDCP and Freesync/Gsync between the computer and the screen makes it quite difficult to build a switch. VGA was primitive, but simple to switch, those times are gone. My computers usually make a fuss if I just switch off the screen and back on, because both sides seem to have some active signaling going on and way too much logic. Ps: USB switches for the KM parts are rather simple though and there is a healthy offering (+ you can build this yourself with some extension cords and a simple USB switch). Also, more and more of my devices move wireless (e.g. audio).
- deleted 9y ago[deleted]
- Animats 9y agoOne of the big remaining users of display switching is the military. When something important is happening on one screen, others need to look at that screen. The military wants switching so they don't get everybody jammed around the screen with the action and abandoning their own stations. Here's the current incarnation of NORAD HQ in Cheyenne Mountain.[1] Such switching goes all the way back to NASA during Apollo. Their system put all the screens on a video cable as cable TV signals. Each console, and other locations around Mission Control and Launch Control, all had channel selectors and could watch any display. Using different technology, that capability was maintained in later control centers. [1] https://en.wikipedia.org/wiki/Tactical_operations_center#/media/File:Norad-control-center.jpg https://en.wikipedia.org/wiki/Tactical_operations_center#/me...
- mark-r 9y agoIf the military needs to spend $1000 on a KVM switch, they won't bat an eye. That's not true for most of the rest of us.
- revelation 9y agoI've seen such kind of "control rooms" where everything was running on VMs anyway and the individual computers were just remote desktops. It's like they say, when it gets too difficult, just add a layer of abstraction. They just went up to software.
- X-Istence 9y agoMy monitor has a KVM built in... http://www.dell.com/en-us/work/shop/dell-34-ultrasharp-curved-monitor-u3417w/apd/210-adtr/monitors-monitor-accessories http://www.dell.com/en-us/work/shop/dell-34-ultrasharp-curve... It has two USB ports that can go to two different computers, and then in the settings you can set it up so that when you switch from one input to another it also switches what the USB devices are connected to. There are 4 USB ports total on the monitor, and they switch from one device to the other. It's great, instead of being a separate box, it's built into the monitor. It's neater.
- merb 9y agowell this monitor also can daisy chain another monitor. which is awesome per se, and actually the daisy chained monitor gets switched aswell. (http://en.community.dell.com/support-forums/peripherals/f/3529/t/19996478 http://en.community.dell.com/support-forums/peripherals/f/35...) but 800 bucks for a monitor :/ I've always looked at these dell monitors. but I never use a external monitor when I'm at home (laptop). But at work my boss would never pay for any of those.
- X-Istence 9y agoI work from home. I bought it for myself because I like having the extra real estate. Best purchase I have made in a long time. Also, I couldn't imagine two of these next to each other, 34" is very large!
- mancerayder 9y agoAre there any not-too-expensive, modern (as in DisplayPort-friendly and USB), hardware KVMs available these days? I started looking into a solution and I ended up shelling out money for Synergy, which was cheaper than the HDMI-or-Displayport-I-forgot KVMs I saw on Amazon, which looked like they were in the 2,300+ range (and with really poor reviews).
- otterpro 9y agoWhat I miss about KVM switch is the ability to switch to another system using a keyboard hotkey, such as double-pressing the "Scroll Lock" key on the keyboard. Most high-end KVM had this feature, so that I could use a hotkey to quickly switch to different system. Once anyone gets used to this, there's no going back to rotary dials or slow physical push buttons, etc. I had 3 or 4 systems connected to KVM and nothing was faster. I've tried using modern HDMI/monitor switchbox/splitter and USB switches, but they require awkward physical reaching for the buttons, as I have to reach out for a button or two, every time I need to switch to another system. The old KVM did this in split second and I didn't even have to think about it, sort of like Vim once you get used to the keys. I was able to work so much faster, switching from one system to another, whenever I needed to. Now, I have to think about it before switching, not that I'm lazy, but I don't want to exert so much energy just to switch to another system. Edit: I also miss PS/2 and VGA, for their ability to switch quickly as well. USB devices and HDMI monitors take awhile to switch.
- sqldba 9y agoJesus that author has a real attitude problem.
- cr0sh 9y agoI read this "article", and a few comments below it - and the replies, and I am just wondering: Who is this "Stanislav", and why are they being so grating on people replying? I mean, I can understand disagreement and correction (ie, the whole "please re-read the article, your question was answered" or "the article already addresses this", etc) - but do they have be such an arrogant a about it? It basically turned me off from reading further - or exploring the rest of the blog.
- eighthnate 9y agoI used to have a KVM to switch between my many boxes with many OSes. Now with virtualization, I have box with a few virtual machines. Now if I want to use windows, debian and freebsd, I don't have to switch between 3 physical boxes, I just have to switch virtual machine windows on one box.