Re: [libvirt] [RFC PATCH 0/8 v2] Summary on block IO throttle

On 10/27/2011 11:45 PM, Eric Blake wrote: >On 10/27/2011 03:12 AM, Lei Li wrote: >>1) Enable the blkio throttling in xml when guest is starting up. >> >>Add blkio throttling in xml as follows: >> >><disk type='file' device='disk'> >><driver name='qemu' type='raw'/> >><source file='/var/lib/libvirt/images/kvm-one.img'/> >><target dev='vda' bus='virtio'/> >><address type='pci' domain='0x0000' bus='0x00' slot='0x05' >>function='0x0'/> >><iotune bps='n'.../> >></disk> >> >>2) Enable blkio throttling setting at guest running time. >> >>virsh blkiothrottle<domain> <device> [--bps<number>] >>[--bps_rd<number>] \ >>[--bps_wr<number>] [--iops<number>] [--iops_rd<number>] >>[--iops_wr<number>] >> >>3) The support to get the current block i/o throttling for a >>device - HMP/QMP. >> >>virsh blkiothrottle<domain> <device> > >Given that the XML is named <iotune> under <disk>, we should >probably name the virsh command 'blkiotune' or 'disk-iotune', not >'blkiothrottle'. > Hi Eric, we used<iothrottle> first, I changed it since Daniel P. Berrange proposed<iotune> for per-disk element instead of<iothrottle> when we discussed at RFC V1. The command 'blkiotune' already exist, supported the cgroups blkio-controller, which handles proportional shares and throughput/iops limits on host block devices, global to the domain, but blkio throttling is specified per-disk and can vary across multiple disks. They are different two mechanism.