This may seem overly obvious, but have you simply run a netstat while the slowdown occurs to see what the box(es) are doing at that point in time?
Alex
On 2011-03-28, at 6:32 PM, mcclnx mcc 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.
>
>
>
> --- 11/3/28 (ä)ïPeter Larsen <plarsen@xxxxxxxxxxxxxxxxxxxxxxx> åéï
>
>> åäè: Peter Larsen <plarsen@xxxxxxxxxxxxxxxxxxxxxxx>
>> äæ: Re: centos server network speed check???
>> æäè: centos@xxxxxxxxxx
>> ææ: 2011å3æ28æ,ä,äå5:41
>> On Tue, 2011-03-29 at 05:13 +0800,
>> mcclnx mcc wrote:
>>> we have several servers on same rack and servers are
>> all inside firewall. Centos version from 4.X to
>> 5.X. sometime the connection are very slow (compare to
>> servers on other racks also inside firewall).
>>>
>>> we discuss with network engineer he ask us use "ping"
>> and traceroute" to check. Both tools response time are
>> good but if we connect through application like Web browser,
>> database, or DELL OPMN tool. The response time is very
>> very slow.
>>>
>>> This situation normally last 4 to 5 hours then it back
>> to normal. Does there has way to check "real" network
>> response time so we can show to network engineer.
>> Otherwise they always say "no problem".
>>
>> miitool and ethtool
>>
>> Check that you're running at the right speed; sometimes bad
>> cables will
>> make the negotiation go bad. Sometimes you just connect to
>> the wrong
>> switch port. You may also note if the switch has hard-set
>> values about
>> the negotiation such as duplex settings. Make sure they
>> match on both
>> ends. You should be full duplex unless there's a very very
>> good network
>> reason not to.
>>
>> Lastly, check ifconfig output. Make sure there's no errors
>> reported. If
>> you have a high error count, it's a good bet the cable is
>> bad or the
>> sync settings are wrong.
>>
>> --
>> Best Regards
>> Peter Larsen
>>
>> Wise words of the day:
>> Showing up is 80% of life.
>> -- Woody Allen
>>
>> -----ååäåååææ-----
>>
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>
>
>
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