Known Limitations

vNIOS for KVM supports most of the features of the Infoblox NIOS appliances, with the following limitations:

• vNIOS appliances run on virtual hardware. They do not have sensors to monitor the physical CPU temperature, fan speed, and system temperature.

• Changing the vNIOS appliance settings through KVM may violate the terms of the vNIOS licensing and support models. The vNIOS appliance may not join the Grid or function properly.

• If you get the message error: Unable to read from monitor: Connection reset by peer when starting a vNIOS instance in KVM hypervisor, check the memory of the hypervisor. Failure to start an instance may be due to the lack of memory.

• At certain times, a power failure (or an unexpected reboot) of the VM host may cause a corruption of the VM guest unless writes are correctly persisted. To do this, you must have an NVRAM-based disk controller on the host system and turn-off disk caching. That is, you must set the value of the disk_cachemodes parameter to writethrough.

  1. To set the cache mode to writethrough, pass the cache=writethrough parameter in the virt-install command.
     
     

  2. To validate this setting in the instance, edit the guest XML file as follows:
     Configure the cache mode by updating the cache parameter inside the driver tag to specify a caching option.
     For example, to set the cache parameter to writethrough: 
     <disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='writethrough'/>
<source file='/home/vms/mygm.qcow2' index='1'/>
<backingStore/>
<target dev='vda' bus='virtio'/>
<alias name='virtio-disk0'/>
><address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/>
</disk>