Machine slow

[Billy A. Pumphrey]

Thanks for the info.  Glad to know that my server (dual 600mhz, 1024
RAM) is not very taxed at all at processing about 2-3k messages per day.

Billy Pumphrey
IT Manager
Wooden & McLaughlin

> -----Original Message-----
> From: MailScanner mailing list [mailto:MAILSCANNER at JISCMAIL.AC.UK] On
> Behalf Of Julian Field
> Sent: Wednesday, May 18, 2005 10:21 AM
> To: MAILSCANNER at JISCMAIL.AC.UK
> Subject: Re: Machine slow
> 
> On 18 May 2005, at 15:48, Steen, Glenn wrote:
> 
> > Billy A. Pumphrey wrote:
> >
> >> Quick verification on load average if I may.
> >>
> >> I do not understand how those numbers work.  They appear not to be
> >> percent usage.
> >>
> >> How do the load average numbers work?
> >> On my mailwatch, my usually is around .60-1.4
> >>
> >> Billy Pumphrey
> >> IT Manager
> >> Wooden & McLaughlin
> >>
> >>
> > (snip)
> >
> > The "load factors" are perhaps the most abused "performance
> > statistics"
> > around... They're just the CPU run queue size (+ running jobs)
> > averages
> > calculated for 1, 5 and 15 minutes. Nice to know and a quick
> > indicator,
> > but nothing else.
> >
> > For example: on a one CPU system a load of 2 might be less than
> > desirable,
> > while on a system with 4 CPUs it shows two CPUs idling away... So
one
> > needs weigh the system as a whole when determining if a certain
> > load is
> > fine or not.
> 
> It's not as simple as that. Jobs can be in the run queue if they are
> waiting for disk or network response. So if you have 10 processes all
> waiting to do DNS lookup, for example, then you will have a load
> greater than 10, but totally idle CPU(s).
> 
> This is why a busy MailScanner having a load of up to about 15 is
> nothing to worry about. It merely means there are 15 processes
> waiting for any of
>      (a) CPU time
>      (b) network response
>      (c) disk i/o.
> And that is a very simple view of it.
> 
> When the figure is over 1, it really doesn't tell you very much of
> any use at all. And all it tells you when it is less than 1 is that
> there is some time when your system is not doing anything.
> 
> --
> Julian Field
> www.MailScanner.info
> Buy the MailScanner book at www.MailScanner.info/store
> PGP footprint: EE81 D763 3DB0 0BFD E1DC 7222 11F6 5947 1415 B654
> 
> ------------------------ MailScanner list ------------------------
> To unsubscribe, email jiscmail at jiscmail.ac.uk with the words:
> 'leave mailscanner' in the body of the email.
> Before posting, read the Wiki (http://wiki.mailscanner.info/) and
> the archives (http://www.jiscmail.ac.uk/lists/mailscanner.html).
> 
> Support MailScanner development - buy the book off the website!

------------------------ MailScanner list ------------------------
To unsubscribe, email jiscmail at jiscmail.ac.uk with the words:
'leave mailscanner' in the body of the email.
Before posting, read the Wiki (http://wiki.mailscanner.info/) and
the archives (http://www.jiscmail.ac.uk/lists/mailscanner.html).

Support MailScanner development - buy the book off the website!