Re: When will ZFS become stable?

On 06/01/2008, Kris Kennaway <kris_at_freebsd.org> wrote:

> That's an assertion directly contradicted by my experience running a
> heavily loaded 8-core i386 package builder.

What is the IO profile of this usage? I'd guess that it's "short
bursts of high activity (archive extraction, installing) followed by
long periods of low activity (compiling)". From what I see on the
lists and somewhat from my own experience, the problem appears more
often when the load is more like "constant high r+w activity",
probably with several users (applications) doing the activity in
parallel.

> Please explain in detail
> the steps you have taken to tune your kernel.

vm.kmem_size="512M"
vm.kmem_size_max="512M"

This should be enough for a 2 GB machine that does other things.

> Do you have the vm_kern.c
> patch applied?

I can confirm that while it delays the panics, it doesn't eliminate
them (this also seems to be the conclusion of several users that have
tested it shortly after it's been posted). The fact that it's not
committed is good enough indication that it's not The Answer.

(And besides, asking users to apply non-committed patches just to run
their systems normally is bad practice :) I can just imagine the
Release Notes: "if you're using ZFS, you'll have to manually patch the
kernel with this patch:..." :)

This close to the -RELEASE, I judge the chances of it being committed are low).