Right now if you are using KVM and Eucalyptus (ie UEC) you can specify the device to the euca-attach-volume command but the system ignores the specified device and attaches to an arbitrary /dev/sd device. This makes scripting of anything beyond a minimal stack of instances almost impossible.
Will the recently announced virtio support with KVM for Eucalyptus 2.0 change this and make it possible to truely specify the device used in a euca-attach-volume command and know that is the actual device configured by the system?
Hello,
it is my understanding that kvm does not support this feature (that is specifying the device name for the block device), so eucalyptus won't be able to support it either if your cluster uses KVM. It is supported with Xen.
chees
graziano
Apparently, the situation with virtio devices is not any different: we tried using "/dev/vdb" to attach a first virtio disk and it was attached as "/dev/vda". It is unfortunate that KVM does not give one control over this even in paravirtualized setting.