Attaching additional disks to virtual machines


I am using Open Nebula 4.12 on Cent OS 6.5 with the KVM hypervisor and my TM driver is SSH (no NFS repos).

Whenever I attempt to attach a datablock (between 150-300 GB) to a running VM, it takes hours. It also takes hours to unattach these disks. Is this normal?

Additionally, can anyone point me to any information that might assist with attaching datablocks to Windows Server 2012 R2 virtual machines? When a disk is attached, it is not recognized by the operating system. However, a SCSI controller with no drivers appears in Device Manager. I believe this may be because the OS image is IDE (hd) and you can only attach SATA/SCSI (sd) type datablocks. Thus, the OS does not have a default SCSI controller and does not know what to do with this new SCSI device.

Does this seem like a correct assumption? Any tips or advice? I have a QCOW Windows 2012 R2 VM that desperately needs more drive space.


Transfer times depends on the interconnection network with the SSH driver. Note that there is a datastore --> hypervisor transfer when attaching, a back when detaching the disk (if it is persistent). You may speed up the process by using volatile disks (but note that volatile disks cannot be saved back), volatile disks are created as opposed to transferred.

I don’t have any pointers for the Windows issue, but you reasoning is correct the devices needs to be SCSI, and probably you need to re-scan the bus from the guest OS.