Subject: Re: swap leakage?
To: Jan-Hinrich Fessel <>
From: John Dyson <>
List: current-users
Date: 11/06/1995 10:19:30
> In message <18453.815621505@BALVENIE.PDL.CS.CMU.EDU>you write:
> > > > I think this problem is real, considering the number of people who have
> > > > reported it.
> > > 
> > > It certainly is real. It's an old problem in the VM code.
> > 
> > And, unless i'm mistaken, it was one of the first problems that the
> > FreeBSD folks fixed in their VM code.  (Granted the fix was a hack...
> > but which is better: "hacked" or "broken"?)
> Maybe they fixed this one, but I like it better the way it works in NetBSD, 
> than in FreeBSD 2.x which crashes our machine up to twice a day ...
Try fixing your hardware -- there are many problems that are very OS
sensitive.  The VM system is most likely not crashing your system.  We
recently had a problem that we thought was a VM system problem on
a "very important" freebsd site -- and a careful analysis is pointing
to a 2bit memory error!!!!  If NetBSD works best for you -- fine, but
buying more memory is not always an option (Triton MBs).  Note that there
are very big sites very very heavily loaded running FreeBSD -- and probably
likewise NetBSD, Linux.  One thing that we have noticed is that users
complaining -- about ready to trash FreeBSD, many times "repent" after
replacing ram chips.  (That isn't to say that there aren't bugs -- it
is just that it is not fair to judge when experiments are not controlled
thereby eliminating other variables.)

Note also there are driver differences -- disk I/O probelms can manifest
themselves as kernel crashes -- since FreeBSD has UPAGE swapping

Best wishes