On Tue 04 Oct 2016 05:51:26 PM CEST, Max Reitz wrote: >> At least giving users a way to skip the math would be an improvement. >> Would you be okay with an explicitly-set option like >> l2_cache_size=auto or =max that optimizes for performance at the >> expense of memory? > > That (cache-size=max) is actually something Stefan Hajnoczi has > proposed at KVM Forum 2015. > > I agree that implementing the formula in qemu's qcow2 driver itself > makes sense and will help users; however, I do think it is appropriate > to expect the user to pass cache-size=max if they need it.
Frank Myhr's suggestion (in bugzilla) is that we allow specifying a % of the disk size, so l2-cache-size=100% (that would be cache-size=max) l2-cache-size=80% ... https://bugzilla.redhat.com/show_bug.cgi?id=1377735#c3 Either one looks good to me. They would change however the data type of 'l2-cache-size' from int to string in BlockdevOptionsQcow2, can we actually do that? Berto
