On Thursday 5 April 2012 at 11:40, Daniel P. Berrange wrote: > On Thu, Apr 05, 2012 at 11:36:55AM +0200, Frido Roose wrote: > > Hello, > > > > I see there is an option with virsh attach-disk to set the cache to "none" for raw devices, but I can't find how to attach the disk with io=native (needed for performance reasons). > > The goal is to attach a disk online, directly with the proper performance settings. > > > > virsh attach-disk is just a wrapper around the more general > command virsh attach-device. So if there's stuff you can't > set with attach-disk, you can always pass the complete XML > to attach-device to set everything > Thanks for the tip... I made a little shell script that allows me to hot-add a device with cache=none and io=native, similar to attack-disk, and it seems to work! Best regards, Frido Roose # cat virsh-attach-disk.sh #!/bin/bash VM=$1 VDX=$2 DEV=$3 if [ -z "$VDX" ] then # try to find out next available vdx device echo "Usage: $0 <vmname> <vdx> <dev>" exit 1 fi XMLFILE=/tmp/virsh-attach-disk.$$.xml echo " <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native'/> <source dev='$DEV'/> <target dev='$VDX' bus='virtio'/> </disk> " >$XMLFILE echo "About to add the following disk config:" cat $XMLFILE echo echo " # virsh attach-device $VM $XMLFILE --persistent" echo echo -n "Apply? [y/n] " read answer if [ "$answer" == "y" -o "$answer" == "Y" ] then virsh attach-device $VM $XMLFILE --persistent else echo "Aborted!" fi rm -f $XMLFILE
