<html><head></head><body>Are the on the same switch?<br><br><div class="gmail_quote">On March 28, 2016 3:00:58 PM EDT, Todor Fassl <fassl.tod@gmail.com> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail">This particular problem, if it is a power problem, has to be caused by <br />something a person could lug into the labs. I've been saying they are <br />in different buildings but, technically, they are on different wings of <br />the same building. I tend to think of them as different buildings <br />because I usually go outdoors to get from one to another. The point is <br />that they are widely separated.<br /><br />I haven't tried to find a pattern in the time of day. I only paid enough <br />attention to the time of the crashes to be certain that there is no <br />obvious pattern. The crashes occur at different times of day and night.<br /><br /><br /><br />On 03/28/2016 01:14 PM, Pete Hardie wrote:<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> I once tracked a bug that was due to the building elevator motors stopping<br /> and starting differently after-hours<br /><br /><b
r /> On
Mon, Mar 28, 2016 at 1:36 PM, Dustin Strickland <<br /> dustin.h.strickland@gmail.com> wrote:<br /><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ad7fa8; padding-left: 1ex;"> The compressors in air conditioning units or refrigerators can also have<br /> an effect when they kick on.<br /><br /> On Mon, Mar 28, 2016 at 1:30 PM, Jim Kinney <jkinney@jimkinney.us> wrote:<br /><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"> Microwave!!!<br /><br /> The EM field from those can cause screens to be wacky, wiggly while they<br /> run . I moved my desk from the opposite side of the wall from the home<br /> microwave and still had to get 10' away to stop interference.<br /><br /> Bit flips happen.<br /><br /> On March 28, 2016 1:20:45 PM EDT, Todor Fassl <fassl.tod@gmail.com><br /> wrote:<br /><br /><blockquote class="gmail_quote" style="margin:
0pt 0pt
1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;"><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<br /> nse is<br /> 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 /><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;"> The most common, if not the only, reason I've seen partitions get marked read-only is when I've had p
ower
glitches that that caused a very brief interruption in connectivity to<br /> the<br /> 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 /> 678-697-9420<br /> james.taylor@eastcobbgroup.com<br /><br /><br /><br /> Todor Fassl <fassl.tod@gmail.com> 3/28/2016 11:54 AM >>><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ccc; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ccc; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ccc; padding-left: 1ex;"><br /></blockquote> I have a mysterious problem with workstations in a shared use<br /></blockquote></blockquote> environment. Th
ere are
2 labs in different buildings, onewith 6<br /> workstations and one with 8. These workstations ar<br /> e used<br /> 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<br /> don't<br /> 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 s
cript
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<br /> ther<br /> 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 /><br /> Ale mailing list<br /> Ale@ale.org<br /> <a href="http://mail.ale.org/mailman/listinfo/ale">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">http://mail.ale.org/mailman/listinfo</a><br /><br /><br /><br /><br /><hr /><br /><br /> Ale mailing list<br /> Ale@ale.org<br /> <a href="http://mail.ale.org/mailman/listinfo/ale">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">http://mail.ale.org/mailman/listinfo</a><br /></blockquote></blockquote><br /><br /> --<br /> Sent from my Android device with K-9 Mail. Please excuse my brevity.<br /><br /><hr /><br /> Ale mailing list<br /> Ale@ale.org<br /> <a href="http://mail.ale.org/mailman/listinfo/ale">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">http://mail.ale.org/mailman/listinfo</a></blockquote><br /><br /><br /><hr /><br /> Ale mailing list<br /> Ale@ale.org<br /> <a href="http://mail.ale.org/mailman/listinfo/ale">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">http://mail.ale.org/mailman/listinfo</a></blockquote><br /><br /><br /><br /><br /><br /><hr /><br /> Ale mailing list<br /> Ale@ale.org<br /> <a
href="http://mail.ale.org/mailman/listinfo/ale">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">http://mail.ale.org/mailman/listinfo</a></blockquote><br /></pre></blockquote></div><br>
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