Il 03/07/2012 15:49, Kevin Wolf ha scritto: >> If the guest does not support flushes, we should run in writethrough mode. >> > The setting is temporary until the next reset, so that for example the >> > BIOS will run in writethrough mode while Linux will run with a writeback >> > cache. >> > >> > VIRTIO_BLK_F_FLUSH has been introduced in Linux 2.6.32 (in 2009) and >> > was backported to RHEL/CentOS 5.6 (in 2010). The Windows drivers have >> > two bugs, which I reported on the Red Hat Bugzilla as bugs 837321 and >> > 837324. With these patches they will suffer a performance hit but >> > gain correctness. >> > >> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > I generally like the idea for a default, but doesn't this override even > an explicit cache=writeback?
Yes. It doesn't override cache=unsafe though. > Are we sure that we want this? The idea is that this change will overcome Anthony's objections to switching the default to writeback... Paolo
