Troubleshooting kernel panic with zfs

[Shane Ambler]

On 21/9/18 10:34 pm, Mike Tancsa wrote:
> 
> Given all the issues with memory pressure perhaps ARC is eating too
> much, I would try artificially limiting it so it does not eat up too
> much RAM.  We had a similar purposed server but with 32G RAM and I found
> one day the system was randomly shooting processes to reclaim RAM
> 
> eg
> pid xxx (yyy), uid zzzz, was killed: out of swap space
> 

I have seen these errors, for me they came when >90% ram is wired.

This is something I reported in bug 229764. While ARC is wired, there is
also a max_wired that limits other wired allocations, these two are
independent and can total more than physical ram.

max_wired defaults to 30% ram, so arc_max should be kept less than 70%

I also had positive results applying review D7538

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

Shane Ambler