Slashdot Mirror
Persistent Terminals For a Dedicated Computing Box?
Theovon writes "I just built a high-end quad-core Linux PC dedicated to number-crunching. Its job is to sit in the corner with no keyboard, mouse, or monitor and do nothing but compute (genetic algorithms, neural nets, and other research). My issue is that I would like to have something like persistent terminal sessions. I've considered using Xvnc in a completely headless configuration (some useful documentation here, here, here, and here). However, for most of my uses, this is overkill. Total waste of memory and compute time. However, if I decided to run FPGA synthesis software under WINE, this will become necessary. Unfortunately, I can't quite figure out how to get persistent X11 session where I'm automatically logged in (or can stay logged in), while maintaining enough security that I don't mind opening the VNC port on my firewall (with a changed port number, of course). I'm also going to check out Xpra, but I've only just heard about it and have no idea how to use it. For the short term, the main need is just terminals. I'd like to be able to connect and see how something is going. One option is to just run things with nohup and then login and 'tail -f' to watch the log file. I've also heard of screen, but I'm unfamiliar with it. Have other Slashdot users encountered this situation? What did you use? What's hard, what's easy, and what works well?"
You think VNC is difficult to set up? Well NX is just absurdly complicated. That one time I managed to get it working, it was indeed vastly superior to VNC, but I just can't fucking understand why they have to install their own damn SSH server and keys. Why? WHY???
How come it's not been picked up by any major distribution? Probably because installing it by following the megabyte-long HOWTOs feels like an exercise in computer masochism.
Why not just run it on the console, and connect a KVM with network access to that sucker?
I use Xvfb to make a virtual screen on the number cruncher (comes with xorg). I don't need to see the display, it just has to be there for wine. If something goes wrong (error box pops up) and there is no progress I take a screen dump of the vortual screen to see it. This eliminates traffic on the network too.
No need to open holes in your firewall except for SSH, which is pretty safe to do.
I would strongly disagree with this statement. Because ssh has the ability to do so much, it deserves special attention to security. The default implementation should be tweaked more than a little bit, including disabling password login, changing the port and, please don't forget, disabling ssh1. There are other, more subtle, cryptographic attacks, but even those few changes should make it more secure.
[quote]Microsoft's remote desktop simply works better than anything in the unix world[/quote]
Sadly, you're not wrong, even though many will refuse to admit it. There's a bit of NIH syndrome going on here and also a general lack of understanding why neither X nor VNC are as functional as Remote Desktop.
Sun's Secure Global Desktop (previously known as SCO Tarantella) actually compares really well in the Unix world, but it's payware even if you need just 1 or 2 seats - functionality that is included with the OS with Remote Desktop. Sun, do all of us, Unix and yourself a favor, and give this product away. Sell licenses to compete with Terminal Server and Citrix, not with Remote Desktop. Pretty please :)
Uh, the original poster talked about persistent X11 sessions. The Sun Rays are perfect for this. The OP can even have one at home set up to connect to his Sun Ray server at work, detach from the session at the end of the day and reconnect to it from home.
Sun Rays are really one of the coolest technologies to come out of Sun in the last 20 years, but unfortunately, they are such a shift from the norm (and until recently needed Solaris on Sparc for the server) that most companies have no idea of their potential. Sun even has gateways to Citrix so that the same little desktop box can display Solaris, Linux, and Windows apps all at the same time.
If only "common" sense was actually that common...