Re: [SLUG] Need a lesson in routing [WAS: memory]

[Tony Sceats <tony.sceats@xxxxxxxxx>]

maybe you should check your interfaces for half/full duplex and if there's
errors or collisions...

otherwise have a play with vmstat, iostat, mpstat etc - they could point you
in a direction to look further, at least it will give you hints to see if
the box is actively swapping (have swapped out data and swapping in/out data
all the time are quite different, as James kinda mentioned)




On Fri, Feb 20, 2009 at 10:57 AM, Kyle <kl@xxxxxxxxxxx> wrote:

> Thanks the response and explanation James.
>
> I get the following, sooo... not _too_ bad I guess from that perspective.
>
> [kyle@bottlenose ~]$ free
>             total       used       free     shared    buffers     cached
> Mem:       2072908    1987788      85120          0     171084    1096132
> -/+ buffers/cache:     720572    1352336
> Swap:      4192944        112    4192832
>
> So I guess I need to look elsewhere as to why my experience is "slow". To
> clarify my thinking, my 'slow' experience relates to the Server/Router
> routing to/from the hosts behind it.
>
> Hosts behind the box timeout frequently when contacting the mail server.
> Likewise HTTP calls through the box seem unusually slow despite an ADSL2+
> running at ~ 15Kbps D'Load connection (noise margin and attentuation seem in
> reasonable levels).  Yet an HTTP call from the Server itself loads fairly
> quickly.
>
> 'route' shows what it needs to show. I have only ever read of one param in
> sysctl.conf that relates to routing. Where do I start to look?
>
> ------------------------------------------------------------------------
> Kind Regards
>
> Kyle
>
>
>
> James Polley wrote:
>
>>
>> You haven't mentioned swap though - is your machine eating into swap?
>>
>> The best solution though is to get more RAM. It's cheap, and it makes
>> everything faster.
>>
>> That is, assuming this is actually your problem....
>>
>> On Fri, Feb 20, 2009 at 8:48 AM, Kyle <kl@xxxxxxxxxxx> wrote:
>>
>>> Hi Slugger's
>>>
>>> It appears I need a lesson in Linux and memory management.
>>>
>>> If you could treat this request as if coming from a complete numpty
>>> please, and simply explain the differences between Cached, Buffered and
>>> Application Memory as they pertain to Linux?
>>>
>>> According to KDE SysGuard, my CentOS 5.2 server appears to "cache" its
>>> entire 2GB quotient of physical RAM. And my general experience of the box
>>> (implemented as file server, mail server, firewall and router) is that it is
>>> slow.
>>>
>>> Something tells me it shouldn't be behaving like this?
>>> --
>>> ------------------------------------------------------------------------
>>> Kind Regards
>>>
>>> Kyle
>>>
>> --
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