[Bug 199189] SWAP on ZFS can crash server

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=199189

--- Comment #6 from John Nielsen <john at jnielsen.net> ---
FWIW, on my test VM with 3GB RAM and a 2GB swap volume (with ZFS properties as
described in my previous comment) the test script hangs the system with the
default settings:
vm.v_free_min: 4833
vm.v_free_target: 16218
vm.v_free_reserved: 1038
vm.v_free_severe: 2935

but not with these (just bumping up v_free_min and v_free_severe):
vm.v_free_min: 8192
vm.v_free_target: 16218
vm.v_free_reserved: 1038
vm.v_free_severe: 7168

On this system the magic number for v_free_severe seems to be between 5120
(which hangs) and 7168 (which doesn't).

I have added a note about vm.v_free_severe to
https://wiki.freebsd.org/RootOnZFS#ZFS_Swap_Volume, which is where I got the
recommended swap volume settings from in the first place.

-- 
You are receiving this mail because:
You are the assignee for the bug.