<div dir="ltr">The compressors in air conditioning units or refrigerators can also have an effect when they kick on.</div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Mar 28, 2016 at 1:30 PM, Jim Kinney <span dir="ltr"><<a href="mailto:jkinney@jimkinney.us" target="_blank">jkinney@jimkinney.us</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>Microwave!!!<br>
<br>
The EM field from those can cause screens to be wacky, wiggly while they run . I moved my desk from the opposite side of the wall from the home microwave and still had to get 10' away to stop interference.<br>
<br>
Bit flips happen.<br><br><div class="gmail_quote"><div><div class="h5">On March 28, 2016 1:20:45 PM EDT, Todor Fassl <<a href="mailto:fassl.tod@gmail.com" target="_blank">fassl.tod@gmail.com</a>> wrote:</div></div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<pre><div><div class="h5"><br>We've run every kind of hardware diagnostic we can think of. Besides, <br>it's just these 14 machines in the 2 shared spaces. Identical machines <br>in private offices don't seem to have any problem.H<br><br>But, you're right. Ssome kind of power problem is the best theory I've <br>seen for a while. The 2 rooms are in different buildings and they never <br>had a problem before. But maybe somebody is plugging something in. Come <br>to think of it, we had a similar problem years ago when a student put a <br>microwave oven in his office. The computers on the other side of the <br>wall kept going down. I don't know enough about electricity to explain <br>that but the microwave oven and the computer were plugged into outlets <br>on opposite sides of the same wall.<br><br>What kind of gizmo would a grad student be bringing into a lab that <br>would make linux workstations freeze up?<br><br>Another reason this theory makes se
nse is
that I haven't gotten a single <br>complaint about the machines going down. You'd think if they were going <br>down while people were using them, I'd get complaints. People are always <br>logged in when they go down but that doesn't mean anything since they <br>tend to walk away w/o logging out. I've looked for patterns in the list <br>of users who were logged in whan a machine went down but didn't see any. <br>I can't rule out that it's somebody doing something though. There might <br>be a pattern and I just didn't see it. But I am sure there isn't one guy <br>who is always logged in whan a machine goes down.<br><br>On 03/28/2016 11:05 AM, James Taylor wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0pt 0pt 1ex 0.8ex;border-left:1px solid #729fcf;padding-left:1ex"><div><div class="h5"> The most common, if not the only, reason I've seen partitions get marked read-only is when I've had power glitches that that caused a very brief interruption in connectivity to
the
drives.<br> Normally that is not an issue with locally attached drives on workstations, but stranger things have happened.<br> Are the workstations on UPS or is the power to the rooms conditioned properly.<br> -jt<br><br><br> James Taylor<br> <a href="tel:678-697-9420" value="+16786979420" target="_blank">678-697-9420</a><br> <a href="mailto:james.taylor@eastcobbgroup.com" target="_blank">james.taylor@eastcobbgroup.com</a><br><br><br><br><blockquote class="gmail_quote" style="margin:0pt 0pt 1ex 0.8ex;border-left:1px solid #ad7fa8;padding-left:1ex"><blockquote class="gmail_quote" style="margin:0pt 0pt 1ex 0.8ex;border-left:1px solid #8ae234;padding-left:1ex"><blockquote class="gmail_quote" style="margin:0pt 0pt 1ex 0.8ex;border-left:1px solid #fcaf3e;padding-left:1ex"> Todor Fassl <<a href="mailto:fassl.tod@gmail.com" target="_blank">fassl.tod@gmail.com</a>> 3/28/2016 11:54 AM >>><br></blockquote></blockquote></blockquote> I have a mysterious problem with workstations in a shared use<br> environment. There are 2 labs in different buildings, onewith 6<br> workstations and one with 8. These workstations ar
e used
by a group of<br> about 30 grad student TAs. All are running ubuntu 15.10. Authentication<br> is via ldap and home directories are mounted via nfs. Every day, 2 or<br> 3 of the machines go down. The earliest symptom I can find is that the<br> root filesystem is remounted read-only. Soon they stop responding to<br> ssh and snmp and they are essentially locked up. They still respond to<br> pings though.<br><br> I've caught the machines in the period where the root system is<br> read-only but I can still ssh to them. I've found that I cannot nfs<br> mount home directories on our file server. I can mount nfs shares on<br> other servers. And I can mount the same home directories if I go to<br> another workstation. Restarting nfs on the file server has no effect.<br><br> When I try to mount a home directory on an effected machine, the mount<br> just hangs. I ran it with strace and it just showed it was waiting --<br> for what, I'm not sure and I
don't
have a screen cap available at the<br> moment. I put a packet sniffer on the server and it showed it received a<br> single packet from the client and that's it.<br><br> There is nothing in the logs on the client. In fact, they simply stop at<br> some point in the process. At first I attributed this to the root<br> filesystem being read-only but it continues after I move /var to a<br> separate file system. At some point it just stops writing records to the<br> syslog but I don't know if it's before or after the root filesystem is<br> remounted read-only.<br><br> Many of the TAs also have identical workstations in their offices. None<br> of those machines seem to have this problem. The TAs do tend to walk<br> away from the workstations w/o logging out. But I wrote a script to kill<br> off their sessions and it didn't help. I had it send me an email<br> whenever it killed somebody's session and it doesn't seem to be<br> correlated with that. In o
ther
words, sometimes machines go down even if<br> everyone who has used it has remembered to log out.<br><br> I'm pretty desperate. Any ideas?<br><br><hr><br></div></div><span class=""> Ale mailing list<br> <a href="mailto:Ale@ale.org" target="_blank">Ale@ale.org</a><br> <a href="http://mail.ale.org/mailman/listinfo/ale" target="_blank">http://mail.ale.org/mailman/listinfo/ale</a><br> See JOBS, ANNOUNCE and SCHOOLS lists at<br> <a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><br><br><br><br><br><hr><br></span><span class=""> Ale mailing list<br> <a href="mailto:Ale@ale.org" target="_blank">Ale@ale.org</a><br> <a href="http://mail.ale.org/mailman/listinfo/ale" target="_blank">http://mail.ale.org/mailman/listinfo/ale</a><br> See JOBS, ANNOUNCE and SCHOOLS lists at<br> <a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a></span></blockquote><br></pre></blockquote></div><span class="HOEnZb"><font color="#888888"><br>
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