lkml.org 
[lkml]   [1999]   [Jun]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Network slow-downs - someone follow this thread this time please!
From
Date



<br><font size=2 face="sans-serif">I'm reposting this information -- I posted it about a month back, but no one seemed to notice. &nbsp;I've solved the problem in the meanwhile the same way that svenden@pvv.org has -- cycling the interfaces. &nbsp;However, it's having to be done every 10 minutes, with a 5 second delay after downing -- HIGHLY annoying, even when done in cron.</font>
<br>
<br><font size=2 face="sans-serif">I've got 3 machines running 2.2.10. &nbsp;2 of the machine are PPro200, 1 is PII 350. &nbsp;All are running 3COM 3C905/905b PCI controllers -- 5 of them in total, 2 running at 10mb, 3 at 100mb.</font>
<br>
<br><font size=2 face="sans-serif">After approximately 2 days of uptime, I will start to see ping times on the local lan jump to 7-20 seconds. &nbsp;As others have noticed, there is no loss -- just some damn high latency. &nbsp;This occurs whether i'm pinging another linux box, a windows box, or a cisco.</font>
<br>
<br><font size=2 face="sans-serif">It seems to be dependant upon the network load -- lighter loads lead to longer periods between problems. &nbsp;The problem ALSO is gradual -- it'll start at 4 second pings, then 7 second pings about 20 minutes later, than 30 minutes later it's up to 12-20 seconds. &nbsp;At this point the machine is almost unusable from remote. &nbsp; The problem doesn't seem to be triggered by data being forwarded -- I can route as much as i want thru the firewall (linux) w/o affecting it, but if the same machine is used for server activities it does begin to display the problem.</font>
<br>
<br><font size=2 face="sans-serif">My kernel is compiled w/gcc version egcs-2.91.66 19990314 (egcs-1.1.2 release)</font>
<br>
<br><font size=2 face="sans-serif">I normally compile the kernel w/ -mpentiumpro, but have gone back to -mpentium for the time being -- that did not change the problem at all.</font>
<br>
<br><font size=2 face="sans-serif">glibc is version 2.1 and 2.1.1, same symptoms under both.</font>
<br>
<br><font size=2 face="sans-serif">The network consists of a handful of windows boxes (98, NT4, Windows 2000), a cisco 2524, and the linux boxes. &nbsp;Nothing is dhcp enabled, ALL nics in all machine are 3com based, and i'm all out of relevant information. :)</font>
<br>
<br>
<br><font size=2 face="sans-serif">David S. Stahl<br>
President, CTCS/Dalsom Inc.<br>
cybertech@cybertech.org</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td>
<td><font size=2 face="sans-serif"><b>svendsen@pvv.org. (Øystein Svendsen)</b></font>
<br><font size=2 face="sans-serif">Sent by: owner-linux-kernel@vger.rutgers.edu</font>
<p><font size=2 face="sans-serif">06/28/1999 11:56 AM</font>
<br>
<td><font size=1 face="Arial">&nbsp; &nbsp; &nbsp; &nbsp; </font>
<br><font size=2 face="sans-serif">&nbsp; &nbsp; &nbsp; &nbsp; To: &nbsp; &nbsp; &nbsp; &nbsp;linux-kernel@vger.rutgers.edu</font>
<br><font size=2 face="sans-serif">&nbsp; &nbsp; &nbsp; &nbsp; cc: &nbsp; &nbsp; &nbsp; &nbsp;(bcc: CyberTech/CTCS)</font>
<br><font size=2 face="sans-serif">&nbsp; &nbsp; &nbsp; &nbsp; Subject: &nbsp; &nbsp; &nbsp; &nbsp;Network slow-downs</font></table>
<br>
<br><font size=2><tt>Hello,<br>
</tt></font>
<br><font size=2><tt>I am experiencing quite drastically slow-downs on the network<br>
performance on a dual P-II system running kernel 2.2.10.<br>
</tt></font>
<br><font size=2><tt>The machine currently has two network cards, one ISA NE2000 clone and<br>
one Intel Ether Express 100 card, which is the card I have trouble<br>
with. &nbsp;The machine works many as NFS-server.<br>
</tt></font>
<br><font size=2><tt>After upgrading to the 2.2 series we have from time to time<br>
experienced severe slow-downs on the TCP performance, down to 1-10% of<br>
the normal performance, measured by ttcp. &nbsp;According to /proc/net/dev,<br>
we have no packet loss when the network slows down.<br>
</tt></font>
<br><font size=2><tt>When using ping from an Ultra 2 running Solaris 2.6, I record an<br>
average ping response ranging from 100 to 4000 milliseconds, but no<br>
loss, the ping response is just slow.<br>
</tt></font>
<br><font size=2><tt>The performance goes back to normal when I take down the interface and<br>
reinsert the eepro100 module into the kernel. &nbsp;After I've done that,<br>
the performance is fine for a couple of days or maybe weeks.<br>
</tt></font>
<br><font size=2><tt>I have tried to just take the interface down with ifconfig without<br>
removing the module, and this seems to fix the problem, but only until<br>
a large file is read through NFS. (I'm using the user level nfsd, but<br>
I have had this problem using knfsd too.)<br>
</tt></font>
<br><font size=2><tt>When I measure the ping response while dd-ing a 60 MB file to<br>
/dev/null through NFS on another machine, the response seems to be<br>
fine until the whole file has been read, then the ping response grows<br>
rapidly up to about an average of 100-200 ms, and after a hour or so<br>
we end up with an average response of 3000-4000 ms.<br>
</tt></font>
<br><font size=2><tt>The traffic that goes through the NE2000-card seems to be unaffected<br>
by what's happening on the eepro100 interface, the ping response is<br>
stable way below 5 ms all time. &nbsp;I used to have an Accton 21140-based<br>
card instead of the eepro100 card, and I experienced the same problems<br>
using that card too.<br>
</tt></font>
<br><font size=2><tt>I have had seen this problem in 2.2.6, 2.2.7, 2.2.9 and 2.2.10.<br>
</tt></font>
<br><font size=2><tt>We have another box which is used as a workstation, but no SMP, and I<br>
have on one occasion seen this problem there, and this box does not<br>
have a SMP enabled kernel.<br>
</tt></font>
<br><font size=2><tt>I am not yet able to find a way to reproduce the problem, but I have<br>
noticed that it somehow seems to be triggered by messing with the nfs<br>
daemon (killing and restarting it, that is).<br>
</tt></font>
<br><font size=2><tt>I hope this is a problem that could be fixed, and I'll be happy to<br>
provide more details, and otherwise do whatever is needed to find out<br>
what's happening.<br>
</tt></font>
<br><font size=2><tt>--<br>
&nbsp; &nbsp;Øystein Svendsen<br>
</tt></font>
<br>
<br><font size=2><tt>-<br>
To unsubscribe from this list: send the line &quot;unsubscribe linux-kernel&quot; in<br>
the body of a message to majordomo@vger.rutgers.edu<br>
Please read the FAQ at http://www.tux.org/lkml/</tt></font>
<br>
<br>
\
 
 \ /
  Last update: 2005-03-22 13:52    [W:0.061 / U:0.532 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site