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2009-03-29, 18:06   #925
Lennart

"Lennart"
Jun 2007

21408 Posts

Quote:
 Originally Posted by mdettweiler Hmm...but doesn't that option only work for brief power outages? I believe my computer is set similarly, but if the power outage is for more than a few seconds then the computer will just stay off when the power comes back on.
No It will start the computer when power comes back.

There use to be a third alternative : Last State.

If computer is on it will start when power is back, if computer is off it stays off.

/Lennart

 2009-03-29, 18:29 #926 henryzz Just call me Henry     "David" Sep 2007 Cambridge (GMT) 130328 Posts it would be worth setting the VNC server to start automatically at startup i think
2009-03-29, 19:57   #927
mdettweiler
A Sunny Moo

Aug 2007
USA (GMT-5)

624910 Posts

Quote:
 Originally Posted by henryzz it would be worth setting the VNC server to start automatically at startup i think
You're right, that would be handy. Now that I think about it, putting it into the respective user's crontab to start at bootup would probably do the trick...I think I'll try that once the systems come back online.

Nonetheless, though, even without having the VNC server started automatically, as long as both the machine I want to connect to, and crunchford, are on, I can still get in through SSH, and from there start the VNC server if necessary. The way we've set it up is so that the only internet-facing remote access port is port 22 on crunchford, that is, SSH. All remote control connections go through port 22 on crunchford--for example, if I want to SSH into one of the other machines, I first SSH to crunchford, and SSH from inside there to the target machine. Or if I want VNC, I run SSH so that it tunnels port 5901 on the respective target machine through crunchford to my machine, and connect to the tunneled port on my machine. (Gary, if you're reading this and none of this makes sense, don't worry, that's because all of this tunneling stuff is taken care of automatically by the Perl script you use to connect to your machines. )

Such a system has its advantages and disadvantages. First of all, it's much more secure to have everything, including the unencrypted VNC connection, be tunneled through an encrypted SSH session. Secondly, the fact that only one machine has to have only one outward-facing port is also a twofold plus: it both minimizes the amount of direct internet exposure for the machines, and also solves the issue of having 10 different machines all wanting to use the same VNC port on the router. The main disadvantage, however, is that if the one machine that's used as a jumping-off point to the others (in this case crunchford) goes down, then all the rest of them, whether they're running or not, can't be accessed remotely, either.

To solve this, I had planned originally to set up a second "gateway machine" on hueford, the second of Gary's 10 quads. My plan was to have the router forward port 2200 on the outside to port 22 on hueford, thus allowing a secondary route into Gary's network in case the primary one went down. Unfortunately, I couldn't get the port forwarding to work in that case for some reason, and I planned to get back and figure it out later but never got around to it.

Of course, all of this is irrelevant if the machines are off anyway due to a power failure...but, nonetheless, it could still be potentially useful in case something happened to crunchford (which has in fact happened a couple times in the past).

Max

 2009-03-29, 20:01 #928 gd_barnes     May 2007 Kansas; USA 2·3·7·241 Posts Oh!! That sounds like a great idea guys. Next weekend after I'm back and settled back in, I'd like to get some more detailed info. on getting the computers to turn themselves back on after an outage. Max, if that works, hopefully we could make it run the VNC server thing too so that we could access them remotely. I'm assuming that even if the machines could turn themselves back on that they couldn't actually start running the programs that they were previously running. Somebody let me know if that is possible to have them restart their programs too after turning themselves back on. That would be something! Bruce, it sounds like some folks in your house are a little "technophobic". I had a girlfriend like that that I finally talked into getting a computer for the 1st time last year. Last I talked to her, she still seemed a little scared of her machine as though she could break it by pressing the wrong keys or something. My ex knows little about the innards of the machines...just how to run them. She knows nothing about Linux. But she's a quite self-sufficient "get it done" type of person. If I step her through what to do, she seems to almost like helping to get them going again. I guess I'm fortunate in that regard. Gary
2009-03-29, 20:11   #929
mdettweiler
A Sunny Moo

Aug 2007
USA (GMT-5)

3×2,083 Posts

Quote:
 Originally Posted by gd_barnes Somebody let me know if that is possible to have them restart their programs too after turning themselves back on. That would be something!
Well...we could possibly set up something through cron (a program in Linux that can be used to automatically run programs on a schedule--I currently use it to automatically refresh the LLRnet status pages and copy off the results files), so that when the computer is rebooted, it will automatically start a particular set of programs. I'll have to look into this some more--maybe I can write a script to automate the process of programming into cron what to restart when the computer is rebooted.

 2009-03-29, 21:50 #930 IronBits I ♥ BOINC!     Oct 2002 Glendale, AZ. (USA) 3×7×53 Posts You should take a cheap/old/slow computer, make sure it has two NICs, about 20GB HDD and install Smoothwall on it as your firewall router, then to your switch. This will make your outside to inside (red/greeen) (public/private) connections rock solid. It's very easy to manage, put it on an UPS, and your golden. Then take that wireless thang you use and put it into your switch so your wireless nodes can be connected. Now you can reset that critter as often as you want, without affecting your entire setup. Max Here is what I use to restart dnetc clients under linux, I'm sure you can mod 'dnetc' for your purposes. Code: Create a file called /etc/rc.d/init.d/dnetc that looks like this: #!/bin/sh if [ -x /root/dnetc ]; then case "$1" in *start) #make sure we're only running one client /root/dnetc/dnetc -quiet -shutdown /root/dnetc/dnetc -quiet & echo "Started distributed.net client" ;; *stop) /root/dnetc/dnetc -quiet -shutdown echo "Stopped distributed.net client" sleep 2 ;; *) echo "Syntax:$0 [start|stop]" exit 1 ;; esac fi exit 0 Then run these commands chmod 755 dnetc ln -s /etc/rc.d/init.d/dnetc /etc/rc.d/rc0.d/K10dnetc ln -s /etc/rc.d/init.d/dnetc /etc/rc.d/rc1.d/K10dnetc ln -s /etc/rc.d/init.d/dnetc /etc/rc.d/rc6.d/K10dnetc ln -s /etc/rc.d/init.d/dnetc /etc/rc.d/rc2.d/S90dnetc ln -s /etc/rc.d/init.d/dnetc /etc/rc.d/rc3.d/S90dnetc ln -s /etc/rc.d/init.d/dnetc /etc/rc.d/rc4.d/S90dnetc ln -s /etc/rc.d/init.d/dnetc /etc/rc.d/rc5.d/S90dnetc Init levels 0,1,6 the client gets killed Init levels 2,3,4,5 the client gets started the default init run level is 3. Now you don't need a monitor, keyboard or mouse, just power and nic cable Last fiddled with by IronBits on 2009-03-29 at 21:56
 2009-03-29, 22:13 #931 kar_bon     Mar 2006 Germany 1010111010002 Posts Gary, there's no need to hassle! complete the 500k-1M sieve range to your planned depth for the whole range! otherwise it's just more work and somewhat confusing for latter proofs! we got enough work on the other 4 servers so everyone can switch to them. it's annoying that you loose about a week of your CPU-power (and a percentage of your power bill!). so our raid for primes is not lost only a weird path to be gone for some days. the holy primes are there.... and we will find them!!!
2009-03-29, 22:23   #932
PCZ

Jun 2006
Chertsey Surrey UK

1011001102 Posts

Quote:
 we got enough work on the other 4 servers so everyone can switch to them.
No thanks it's a PITA changing the config files.

 2009-03-29, 22:52 #933 gd_barnes     May 2007 Kansas; USA 236128 Posts Good news: Sherri is going over to my place either tonight or tomorrow night to turn on my machines. That means either very early Monday or Tuesday morning, I'll be able to get them running again. Bryan, I hear you about it being a PITA to change many machines over to a different server so we'll do what we have to to avoid running port 8000 dry. Karsten, the plan has been to sieve n=500K-600K to P=15T and put it in port 8000 with n=600K-1M sieved to P=30T. If I can get my machines started in time, I THINK I'll have the sieving to P=15T done in time before we need to load the next range into port 8000. It had been scheduled to complete at about this very moment so I've lost about a day now. If I get my machines restarted early Tues. morning, sieving should be done by Weds. I think that will be in time before port 8000 runs dry. By doing it that way, we only 2 different sieve depths for the n=500K-1M range...not too bad of an admin effort. If anyone wouldn't mind moving a few cores away from port 8000 for just a few days; perhaps move them over to port 5000; that would give me a little breathing room to finish the sieving. I had it all planned out timing-wise until the friggin power outage. Blast! Gary Last fiddled with by gd_barnes on 2009-03-29 at 22:53
 2009-03-30, 00:33 #934 PCZ     Jun 2006 Chertsey Surrey UK 1011001102 Posts I will move the majority of the clients over to the server at home to do some work on my reserved K's.
 2009-03-30, 23:58 #935 gd_barnes     May 2007 Kansas; USA 2×3×7×241 Posts I have some good news. I have no blown mobos and the problem with my machines was a simple power outage early Sat. evening. Sherri has turned them all back on and did the "Start VCN server" thing on 8 of them including Crunchford. On the other 2, one was getting that stupid "analog input error" thing on the screen that I seem to have problems with from time to time (turning machine off and on usually gets rid of it but didn't this time) and on the other, after 2 attempts of unplugging the mouse from various places, she couldn't seem to get mouse access so it's sitting at the log on screen. Max, with Crunchford on now, I tried accessing them remotely...no luck. I assume that you need to do some behind-the-scenes stuff so that I can access them. Can you take care of that as well as restarting ports GB4000 and GB8000? Thanks. If you can do that, after about 3 AM EDT, I'll get my machines crunching again. I think I'll be able to finish the sieving by Weds. just before we'll need a new file for port IB8000. Gary

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