On 08/16/2012 05:54 PM, Martin Wawro wrote: > > On Aug 15, 2012, at 2:57 PM, Avi Kivity wrote: > >>> >>> We are using logical volumes and the cache is set to 'none'. >> >> Strange, that should work without any buffering. >> >> What the contents of >> >> /sys/block/sda/queue/hw_sector_size >> >> and >> >> /sys/block/sda/queue/logical_block_size >> >> ? >> > > Hi Avi, > > It seems that the kernel on that particular machine is too old, those entries > are > not featured. We checked on a comparable setup with a newer kernel and both > entries > were set to 512. > > We also did have a third more thorough look on the caching. It turns out that > the > virt-manager does not seem to honor the caching adjusted in the GUI correctly. > We disabled caching on all virtual devices for this particular VM and checking > with "ps -fxal" revealed, that only one of those devices (and a rather small > one too) > had this set. We corrected this in the XML file directly and the buffer size > currently resides at around 1.8 GB after rebooting the VM (the only virtio > device > not having the cache=none option set is now the (non-mounted) cdrom). >
cc += libvirt-list Is there a reason that cdroms don't get cache=none? -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
