If you think the issue is with network latency. Try using smokeping. If all of the servers are on the same rack, the switch could be overloaded. Check the other servers connected to the switch when the slow down happens. The switch could be overloaded. On Mon, Mar 28, 2011 at 11:33 PM, Emmanuel Noobadmin <centos.admin at gmail.com > wrote: > On 3/29/11, mcclnx mcc <mcclnx at yahoo.com.tw> wrote: > > I don't think it is cable problem. The reason are: > > > > 1. it happen every 3 to 4 weeks once. > > > > 2. problem last 4 to 5 hours then back to normal. > > > > 3. not one server has this problem, several servers on that rack all have > > problem at same time. > > Did you note down the exact dates and times of the past few > occurrences? Have you checked crontab to see if anything is scheduled > to run during those times, e.g. monthly backup set for the wrong time > such as 2pm instead of 2am. > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > -- -- Do not meddle in the affairs of dragons cause you are crunchy and good with ketchup. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20110329/2bdffd9e/attachment-0005.html>