Re: Using swap though there's plenty of mem free

["Dave B." <spam%y2008.dberg.net@localhost>]

On Tue, May 06, 2008 at 02:25:19PM +0200, Jonathan Schleifer wrote:
...
> Usually, there is more free mem on that machine than swap used, 99% of
> the times I look at top.

  How willing to explore various options are you?

  I've never tried it myself, but pkgsrc/sysutils/swapd once caught
my eye.

  Looks like coordinating it with NetBSD's UVM tuning might be a
bit of an art (namely, tune things not-quite-right, and file cache
utilization suddenly triggers creation of a dynamic swap file...);
but people are apparently using it with NetBSD nevertheless.

  Anyway, if you really have enough RAM most of the time, you could
set your system up to remove all statically configured swap devices
upon reaching full, multi-user runlevel successfully (or, just un-
configure static swap devices entirely, provided you're sure you
have the RAM for all critical boot-related activity, e.g., fsck--I
do this occasionally myself... but apparently I like to live on the
edge that way) and let swapd manage things from there.

  Then--I imagine--the OS will do its utmost to keep everything in
RAM.  If ever it can't--i.e., free memory drops below the "minfree"
setting of swapd: swapd adds a new swapfile to compensate (and
removes it later, as resources permit).

  If you do try it, let me know how it is.

Cheers,  --Dave B.
Boston, MA