[oneadmin@opennebula ~]$ vi /srv/cloud/one/etc/vmm_exec/vmm_exec_kvm.conf
OS = [ boot = "hd", arch = "i686" ]
FEATURES = [ PAE = "no", ACPI = "yes" ]
DISK = [ driver = "raw" , cache = "none"]
#NIC = [ filter = "clean-traffic" ]
说明：
默认情况下：cache=default，使用write though规则。将chahe=none后数据可以直接写到磁盘上。
修改该配置后重启one服务使其生效。