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Date: Tue, 8 Jan 2008 07:56:17 +0000
From: David Taylor <davidt@yadt.co.uk>
To: Adam McDougall <mcdouga9@egr.msu.edu>
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Cc: freebsd-current@FreeBSD.org
Subject: Re: Should we simply disallow ZFS on FreeBSD/i386?
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On Sun, 06 Jan 2008, Adam McDougall wrote:
> 
> The amount of kmem required for a particular workload on any one machine can vary 
> alot.  Believe it or not, it is one of my AMD64 systems that I had to increase kmem 
> to 1.6G to prevent kmem panics (it does some heavy nightly rsyncs); versus just 
> having kmem set to 1G on a i386 system that constantly serves out files to the 
> internet with various rsyncs running through the day. 

Note that you're probably running into an integer overflow in arc.c
if vm.kmem_size is set to 1GB or higher on i386.  As a result 
kstat.zfs.misc.arcstats.size won't grow above
kstat.zfs.misc.arcstats.c_min...

I posted to freebsd-fs about it, but haven't heard anything from pjd, yet. 

Sadly, after fixing that problem I started encountering the kmem_map
too small panics.

-- 
David Taylor