On Tue, Jan 17, 2017 at 3:10 PM, Matthew Miller
<mattdm(a)fedoraproject.org> wrote:
On Tue, Jan 17, 2017 at 12:50:43PM -0500, Josh Boyer wrote:
> > Well, I'm starting from Michael's premise that deadline would be better
> > for latency for most desktop users (regardless of disk type), and
> > clearly better when using SSD. This leads me to a different conclusion
> > than the above.
> Then set it as such in Workstation. I don't see how your conclusion
> conflicts with mine at all.
Well, if it seems like the best default for Workstation (and therefore
probably also most of the desktop Spins) *and* for server, doesn't
changing the overall default make the most sense?
Via the runtime tunable, sure (read that as: we are not carrying a
damn kernel patch). But to assume that it makes sense without at
least discussing it with the Editions seems odd.
> > It's irrelevant for cloud and any other virt deployment
of Atomic or
> > Server. As far as I know, the special case on hardware where cfq is
> > better is the one I outlined (on hardware, single spindle, prefer
> > throughput, mixed workload) and I agree that it's okay to expect
> > sysadmins to handle that.
> Why is it irrelevant on virt? Do people not care about local storage
> impacts of their guests? That would be surprising.
It's relevant to virt hosts, but not to cloud and virt _guests_, where
the io scheduler is bypassed completely. See
http://www.linux-kvm.org/images/6/63/02x06a-VirtioBlk.pdf
Is that the default IO driver in QEMU across all releases at this point?
josh