Oracle Audio Technologies E10898-02 - Manual (Page 90)

Quality of Service (QoS)
C-2 Oracle VM Server User's Guide
network interface card (NIC) and you can control how much bandwidth is available to
the virtual network interface. You can also control the I/O priority of a guest’s virtual
disk(s).
This section contains:
■
Setting Disk Priority
■
Setting Inbound Network Traffic Priority
■
Setting Outbound Network Traffic Priority
You can set QoS parameters in Oracle VM Server, and in Oracle VM Manager. See the
Oracle VM Manager User's Guide for information on setting QoS parameters in Oracle
VM Manager.
C.2.1 Setting Disk Priority
You can set the priority of a guest’s virtual disk(s). Eight priority levels are available to
set the time slice a process receives in each scheduling window. The priority argument
is from 0 to 7; the lower the number, the higher the priority. Virtual disks running at
the same priority are served in a round-robin fashion.
The virtual disk priority is controlled with the disk_other_config parameter in the
guest’s configuration file (vm.cfg). The disk_other_config parameter is entered as
a list; each list item represents a QoS setting. The syntax to use for the disk_other_
config parameter is:
disk_other_config = [[ ' front_end ', ' qos_algorithm_type ', ' qos_algorithm_params ']]
front_end is the front end name of the virtual disk device to which you want to apply
QoS. For example,
hda , hdb , xvda , and so on.
qos_algorithm_type is the QoS algorithm. Only ionice is currently supported.
qos_algorithm_params are the parameters for the qos_algorithm_type. For the ionice
algorithm, this may be the schedule class and the priority, for example
sched=best-effort,prio=5 .
For example:
disk_other_config = [['hda', 'ionice', 'sched=best-effort,prio=5'], ['hdb',
'ionice', 'sched=best-effort,prio=6']]
If you make a change to a running guest’s configuration file, you must shut down the
guest, then start it again with the
xm create vm.cfg command for the change to
take effect. The xm reboot command does not restart the guest with the new
configuration.
C.2.2 Setting Inbound Network Traffic Priority
You can set the priority of inbound network traffic for a guest. The inbound network
traffic priority is controlled with the
vif_other_config parameter in the guest’s
configuration file (vm.cfg). The vif_other_config parameter is entered as a list;
each list item represents a QoS setting. The syntax to use for the vif_other_config
parameter is:
vif_other_config = [[ ' mac ', ' qos_algorithm_type ', ' qos_algorithm_params ']]
mac is the MAC address of the virtual network device to which you want to apply
QoS.