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From: Victor on 7 Apr 2010 16:12
On Apr 5, 8:09 pm, Darren Dunham <darren.dun...(a)gmail.com> wrote:
> On Mar 31, 1:18 pm, v_borch...(a)despammed.com (Volker Borchert) wrote:
>
> > Casper H.S. Dik wrote:
> > > The kernel will use all memory for caching or other memory uses.
>
> > > "Free memory" is wasted memory; all files access will be cached until
> > > the memory is needed somewhere else.
>
> > Does the old rule of thumb
> >   "sr > 100 for prolonged periods of time indicates memory shortage"
> > still hold? Perhaps for a value other than 100?
>
> No, that's a pre-Solaris 8 figure.  Since Solaris 8, the page scanner
> should never run unless you have a memory shortfall.  Well, I guess if
> you consider 0 just a different value than 100, then yes.  But that
> old figure was wrong in so many ways.
>
> --
> Darren

Agree. Had a test on Sol10. When available memory is about
LOTSFREE(1/64 of physical memory) and system needs more memory, scan
rate varies from 8000 to 600000 and scanning can finish in 10s for 1GB
memory.

Victor
From: Boardy on 11 Apr 2010 18:04
On Apr 8, 8:12 am, Victor <victorfeng1...(a)yahoo.com> wrote:
> On Apr 5, 8:09 pm, Darren Dunham <darren.dun...(a)gmail.com> wrote:
>
>
>
> > On Mar 31, 1:18 pm, v_borch...(a)despammed.com (Volker Borchert) wrote:
>
> > > Casper H.S. Dik wrote:
> > > > The kernel will use all memory for caching or other memory uses.
>
> > > > "Free memory" is wasted memory; all files access will be cached until
> > > > the memory is needed somewhere else.
>
> > > Does the old rule of thumb
> > >   "sr > 100 for prolonged periods of time indicates memory shortage"
> > > still hold? Perhaps for a value other than 100?
>
> > No, that's a pre-Solaris 8 figure.  Since Solaris 8, the page scanner
> > should never run unless you have a memory shortfall.  Well, I guess if
> > you consider 0 just a different value than 100, then yes.  But that
> > old figure was wrong in so many ways.
>
> > --
> > Darren
>
> Agree. Had a test on Sol10. When available memory is about
> LOTSFREE(1/64 of physical memory) and system needs more memory, scan
> rate varies from 8000 to 600000 and scanning can finish in 10s for 1GB
> memory.
>
> Victor

Thanks everyone for your comments.

I think I'll set my monitoring to alert first at LOTSFREE i.e the
greater of 1/64 of physical memory or 512KB and the second at DESFREE
i.e. LOTSFREE/2.

JB
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