[Qemu-discuss] VM tuning

[Stephan von Krawczynski]

Hello all,

I try to setup a box with 128GB and 32 cpus split into 2 numa nodes. I found
out that while copying a large file to the host some of the qemu guests start
choking. I guess this is because of the vm cache setup.
The probably most important two tunables are:

vm.dirty_background_ratio = 10
vm.dirty_ratio = 20

which is the ditros/kernels (3.11.2) standard setup.
Does anybody have a better idea about these for such a setup?
The guests mem sizes btw sum up to around half of the physical mem, the rest
is used as cache.

-- 
Regards,
Stephan