Subject: Re: Finally increasing vm.execmin by default
To: Todd Vierling <tv@duh.org>
From: Alistair Crooks <agc@pkgsrc.org>
List: tech-kern
Date: 11/01/2005 08:00:55
On Fri, Oct 28, 2005 at 03:49:23PM -0400, Todd Vierling wrote:
> On Fri, 28 Oct 2005, Geert Hendrickx wrote:
> 
> > Is it possible at all to find a sane default for _all_ kinds of systems?
> > Maybe we should, like Peter already proposed in the previous thread, define
> > different sets of defaults, for different usage profiles and/or amounts of
> > memory, among which the user can choose at install-time, and then sysinst
> > would install an apropriate /etc/sysctl.conf.
> 
> I have nothing against populating sysctl.conf with sysinst.  However, the
> defaults compiled into the kernel should work reasonably in between
> tuned-for-workstation and tuned-for-server on the majority of hardware, even
> if sysctl.conf is completely missing.

Just to be boring, how about a sysctl.conf which is populated with
commented out entries, to make it easier for people to tune their
machine post install. Machines have been known to change their uses,
get populated with memory, or install on one disk on one machine for
another.

I'm thinking of something like:

# taken from http://mail-index.netbsd.org/tech-kern/2005/03/06/0004.html
# for database (and other) servers
vm.anonmax=90
vm.anonmin=80
vm.execmax=30
vm.execmin=5
vm.filemax=20
vm.filemin=5

# taken from Message-ID: <Pine.NEB.4.63.0510281108230.974@server.duh.org>
# "compromise settings"
vm.anonmax=70
vm.anonmin=10
vm.execmax=40
vm.execmin=20
vm.filemax=40
vm.filemin=10

# embedded use...

# etc...

or another approach would be to have suggested tuning based on memory
available.

# RAM <= 32MB
...

# RAM 32MB -> 256 MB
...

# RAM 256 MB -> 1 GB
...

# RAM > 1GB
...

Looking to the future, we could start off with something like this,
and then move to automatic sizing at startup, if RAM-based sizing
proves useful. I still think a "usage" component is useful, though.

Regards,
Alistair