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Subject: Re: Disk/ZFS activity crash on 11.2-STABLE [SOLVED]
To: Mike Tancsa <mike@sentex.net>, Jim Long <list@museum.rain.com>
Cc: freebsd-questions@freebsd.org
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From: Shane Ambler <FreeBSD@ShaneWare.Biz>
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Date: Sat, 14 Jul 2018 15:11:21 +0930
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On 14/07/2018 04:52, Mike Tancsa wrote:
> On 7/13/2018 3:10 PM, Jim Long wrote:
>>
>> It appears that limiting the ARC size did it.  The 'zfs send -R' was
>> able to complete with ARC limited to 50G, and a second run with a 60G
>> ARC limit also completed.
> 
> Great! I am glad that helped. Its helpful to me too as I have some
> systems I am upgrading to RELENG_11 from RELENG_10 soon.  I was aware of
> this particular issue, but was worried perhaps your crashes were related
> to something else I might run into :)

To add my 2c -

I recently realised that the arc_max defaults allow all ram to be
allocated as wired, which is bad.

arc_max should not be set higher than physical ram - max_wired - buffer

It is time I put this into a bug report -
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229764

-- 
FreeBSD - the place to B...Storing Data

Shane Ambler