[PATCH] Simple ARC stats in top

John Baldwin jhb at freebsd.org
Tue Jun 26 20:42:40 UTC 2012


On Tuesday, June 26, 2012 12:08:50 pm Andriy Gapon wrote:
> on 26/06/2012 18:57 Mark Felder said the following:
> > On Tue, 26 Jun 2012 10:55:12 -0500, Andriy Gapon <avg at freebsd.org> wrote:
> > 
> >> Does your system also has L2 ARC?
> >> If so, could you please show a value of 
kstat.zfs.misc.arcstats.l2_hdr_size?
> >> Otherwise, it's hard for me to explain the huge difference between Max 
Size and
> >> ARC Size.
> > 
> > Yes, it does.
> > 
> > zfs2# sysctl kstat.zfs.misc.arcstats.l2_hdr_size
> > kstat.zfs.misc.arcstats.l2_hdr_size: 6775072568
> 
> Aha, so no mystery, those 6G in ARC are actually used by L2ARC headers.
> I missed the L2 headers because I haven't used L2 yet.
> I've updated arc-sizes.sh script now to account for these headers.
> 
> So the correct ARC size breakdown is: hdr_size + data_size + other_size +
> l2_hdr_size, where data_size can further be broken down to mfu_size + 
mru_size +
> anon_size.

Hmm, I think for top I should just use hdr_size + l2_hdr_size for "Headers"?
I don't think we have room for more types.  

I've updated top_arc.patch to take that approach.

-- 
John Baldwin


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