Subject: Re: large disk preformance (interactive lags in 1.5.1-BETA)
To: =?iso-8859-1?Q?Jarom=EDr?= Dolecek <>
From: Ken Wellsch <>
List: current-users
Date: 04/09/2001 15:22:45
"Jaromír Dolecek" wrote:
> NetBSD -current has integrated UBC, so it uses all available machine
> memory as I/O buffers automatically. Thus, the reponsiveness
> should be (much) better on -current for your scenario (plenty of RAM,
> slow disk).

What I've been seeing is that after a certain period of time, with something
like a tar unpacking a large tar.gz bundle (e.g. pkgsrc.tar.gz), that UBC
or someone, is merrily consuming *all* available memory and leading to
quiet processes getting swapped out. Thus after running something consumptive
like that for several minutes, getting response from your shell or some
other activity that hasn't been active for a while, is delayed until
it can get some resources back.

Maybe I'm just seeing things, but after many "make build"s on various
systems over several months, I find when looking, that a great many
processes have been nearly "fully" swapped out.

I could see using "most" of available memory, but tuning is a challenge
I'll bet.  Especially if something else is noticing available memory is
getting low and starts to worry and swap stuff out - then UBC just grabs
that too B^)


-- Ken