SOLVED: Simple swap question

[Jerry McAllister]

On Fri, Dec 19, 2008 at 10:37:46AM -0500, FreeBSD wrote:

> Jerry McAllister a écrit :
> >On Thu, Dec 18, 2008 at 12:02:06PM -0500, FreeBSD wrote:
> >
> >  
> >>Daniel Bye a écrit :
> >>    
> >>>On Thu, Dec 18, 2008 at 10:28:18AM -0600, Kirk Strauser wrote:
> >>>      
> >>>>On Thursday 18 December 2008 09:16:10 FreeBSD wrote:
> >>>>        
> >>>>>Hi everyone,
> >>>>>
> >>>>>I have a FreeBSD 7.0-Release server that started to swap after an error
> >>>>>in a shell script (process spawning competition ;-) ). I killed the
> >>>>>shell and the RAM is now OK. The problem is that the swap is still 
> >>>>>used.
> >>>>>How can I "reset" the swap?
> >>>>>          
> >>>>You don't.  The system will handle it for you, I promise.  :-)
> >>>>        
> >>>And very well, too.
> >>>
> >>>You can prompt it to move pages back into RAM if you start using a 
> >>>swapped-
> >>>out process again - say, for example, a quiescent word processor had been
> >>>swapped out, you could get it back by raising it and starting to type.
> >>>
> >>>But as Kirk said, there really is no need. It's one of the kernel's many
> >>>jobs, and I'm inclined to leave it get on with it!
> >>>
> >>>Dan
> >>>
> >>>      
> >>Thanks for your answer. I'm asking here because it's been several days 
> >>and there is still used swap for data that should never be used anymore. 
> >>If the kernel wants to keep it, why not move it to RAM now that there is 
> >>some free?
> >>    
> >
> >Why bother if it isn't being currently used?
> >
> >////jerry
> >
> >  
> Because this server is monitored by Nagios and it emails me every hour a 
> warning because the swap is not 100% free (I know it's pretty extreme, 
> but I want to know if the system is swapping).
> 
> I just tried
> 
> swapoff -a ; swapon -a
> 
> and it worked great.
> 
> Thanks everyone for your answer.
> 
> Martin
> 

But, you want it to use swap.   The system uses swap to stash stuff
it is not currently using - where it can move it back in to use in
a much more efficient, fast manner than re-looking it up again
on filesystem disk.

////jerry
   
> 
>