Re: [gentoo-user] Re: Long standing problem of booting thu kvm switch

[Stroller]

On 17/12/2010, at 5:58pm, Harry Putnam wrote:
> ...
> ps - You were bragging about the abilities of you KVM switch in the
> past thread... I didn't see it mentioned what switch that is.
>
> Also you mentioned accessing your KVM with a web browser... can you
> enlarge a few details on that?


Let me start by saying that I looked up your KVM and was really impressed by it. Yours is the Iogear, right? Not Iomega, I think. I was really impressed that yours is all current technology, switching DVI port as well as mic & speakers, that it uses USB keyboard & mouse.

My current model is a Blackbox KV9408A, back then I was still using my Austin Hughes IP-802.

Basically, both are 8-port KVM switches with a framegrabber and some embedded Linux built on the same board. So the switch part allows you to manage multiple servers, and the framegrabber part allows this to be viewed across the network using a VNC client.

I don't KVM at my desktop, I only use my main desktop machine there. The KVM-IP resides in the server closet, and can switch between my otherwise-headless machines there. It works really well for me, because a lot of my work is (or has been, at least) working on Windows PCs for small offices and home users. So if I bring in one of their PCs to recover data off it, run chkdisk or reinstall Windows, I just shove it in the closet and connect remotely. I don't have to cross the room or twist around in my seat to view the machine I'm working on, it just appears as a large window on the screen of one of the monitors of my desktop PC.

I think this is *really* cool technology. There's something about it that appeals to me that I rate it on the same level of "killer app" as email and ssh. I practically fetishise it.

These IP-KVMs cost c £1000 new, but you can pick them up on eBay for a song. I paid £100 for the Blackbox and I think c £120 for the Austin Hughes. The Blackbox is a little newer, I think, and initially more impressive to use, but overall the features of the two are about even. The web-interface of the Austin H looks a little dated now (it's a 2003 model), but it has the nifty programmable GUI buttons which I mentioned in the previous thread - with them you can create single-button shortcuts for any keyboard macro, and it also has a full on-screen keyboard for occasional use. I find the lack of that a real shortcoming in the Blackbox - this week I was unable to change some BIOS settings remotely because my MacBook's keyboard has no page-up / page-down keys. However the Blackbox just wins the comparison by a nose because it allows you to use any standard VNC client to view the servers - the Austin H requires you to use a browser-launched Java viewer. 

I could spend hours writing a comparison between the two products, because clearly I'm a fanboi for this technology. The two models do the same job, but it's interesting to observe that they have a bunch of implementation differences, and these have a range of more or less subtle benefits and annoyances. 

The market for these devices is fairly niche, I guess - it's impossible to find reviews of them before buying, and hard to learn anything at all about specific models, beyond manufacturers' brochures. A manual doesn't really give you much of an impression of how it is to actually use a particular KVM-IP. I imagine these are sold primarily to datacentres and the enterprise, companies who are buying 10 or 100 at a time, that they are serenaded by salesmen, and that the admins get to try a demo model, perhaps several, before buying them. I wouldn't be surprised if Alan has a few KVM-IPs, or can access his London / Paris / New York / Tokyo servers using them; I would be *extremely* interested to know what models he uses and what he thinks of them.

The retail price is certainly prohibitive unless you've got a pressing business need for a KVM-IP, but as an enthusiast I can easily justify them secondhand. For me, bringing customer's PCs home to work on, they have been *so* useful. I continue to watch eBay for new listings - the only way to compare a new unit with my current one is to try it, and I don't think I'll lose anything on the deal if I manage to snipe an auction and then have a little patience in selling the unwanted unit locally or as a buy-it-now listing. 

Dell servers feature a similar technology which they call DRAC, which is a single embedded card per-server and which is not cheap. But it additionally allows you to power the server on and off and also to mount a .iso image in a virtual CD-ROM device across the network. So you can reconfigure the BIOS and hardware RAID array, then boot the server from this virtual CD drive and reinstall the o/s across the internet without any need for anyone to physically touch the machine. If the installation - or a kernel upgrade or anything else - goes wrong then you can intervene remotely and boot from a system rescue CD or whatever. I've used DRAC4 (early x86-64, Poweredge 1850, 2800, 2850) and DRAC6 Enterprise (current models; the "Express" version isn't really a full DRAC) on a customer's machines. In a Windows environment the DRAC4 is *gorgeous*; the viewer client doesn't work on a Mac, but I think it does on supported Linux configurations (i.e. enterprisey RedHat). The DRAC6 adds an SDcard and I think the idea is that you should be able to load .iso images on this and use them to boot the system; thus there's less data to transfer between London and New York and it doesn't break if you get disconnected during the install. I never got it to work, despite a protracted support email exchange with Dell.

Newer KVM-IP switches feature virtual USB optical drives, but not (in much of a useful form) any of the really cheap ones that I've seen on eBay so far. I think most have a serial port which you can use to operate an external power bar.

Hope this was of interest to you. You can see this is a subject that I love talking about, and I guess I want to evangelise about it a little.

Stroller.