Re: When will ZFS become stable?

From: Kris Kennaway <kris_at_FreeBSD.org>
Date: Sun, 06 Jan 2008 16:08:57 +0100
Ivan Voras wrote:
> 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.

This is a high I/O environment including lots of parallel activity.

>> 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.

No, clearly it is not enough (and you claimed previously to have done 
more tuning than this).  I have it set to 600MB on the i386 system with 
a 1.5GB KVA.  Both were necessary.

>> 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.

It is planned to be committed.  Pawel has been away for a while.

> (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:..." :)

ZFS already tells you up front that it's experimental code and likely to 
have problems.  Users of 7.0-RELEASE should not have unrealistic 
expectations.

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

Perhaps, but that only applies to 7.0-RELEASE.

Kris
Received on Sun Jan 06 2008 - 14:08:59 UTC

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