Limiting ZFS ARC Size?

Bob Willcox bob at
Sun Jun 24 12:18:22 UTC 2018

On Sun, Jun 24, 2018 at 09:32:41AM +0100, james wrote:
> On 18/06/2018 17:24, Bob Willcox wrote:
> > to the point where my running processes (such as firefox) start page
> > thrashing.
> I thought ARC was supposed to give up memory if there is memory pressure 
> that causes applications to page?

That was what I was expecting as well. However ARC had consumed most of the
memory (about 25G, 30G was wired) and firefox was paging like crazy. I did
discover what program was causing ARC to grow seeming unbounded, it was vlc.
I have something over 64k audio tracks that I had pointed vlc to with shuffle
set. It must be recursively reading all of the files in the heirarchy and zfs
is cacheing a bunch of data as it goes.


Bob Willcox    | Isn't air travel wonderful?
bob at | Breakfast in London, dinner in New York,
Austin, TX     | luggage in Brazil.

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