On 21/06/2017 16:21, Douglas Miller wrote: > The problem I have seen is that the standard SCSI driver has a default > timeout on I/O of 30 seconds. But when this driver is used on a KVM > guest via virtio-scsi, the host should be controlling the timeout based > on the actual type of media, and those timeouts may need to be longer. > The KVM guest 'sd' I/O then happily timeout at 30 seconds and try to > abort the commands. With a heavy I/O load it become likely that an abort > will also timeout and this leads to fatal errors like filesystems going > offline. > > It seems that the virtio-scsi driver should disable the 'sd' timeout and > allow the host to handle that. Maybe this has been done already and just > not been backported to distros, but is it reasonable to disable the 'sd' > timeout in KVM guests? Or at least should the default timeout be > increased to a much larger value? Actually that patch has been posted, but never committed. I have just sent it again. Paolo
