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I have seen this issue on Linux VMs too. A reboot of the VM instance helps workaround this.

From: Zuo Changqian [mailto:dummyhacker85 at gmail.com]
Sent: Tuesday, February 25, 2014 10:34 PM
To: Openstack at lists.openstack.org
Subject: [Openstack] [Nova] KVM Windows Guest disk hot plugging support.

Hi

Currently we use Cpeh RBD as cinder volume. According to http://www.linux-kvm.org/page/Hotadd_pci_devices, we have Linux KVM guest (both CentOS 6.x and Ubuntu 12.04) support disk hot plugging, it works well.
But there is problem with Windows 2008 guest (2003 not tested). Described below:

1) Launch an Windows 2008 instance (with RedHat Virtio Driver installed), and attach a volume (newly created with nothing inside) to it, the volume would be successfully attached to /dev/vdb.
2) In Windows (guest machine), format this newly added disk. After formatting, it will show up in "My Computer" windows. Create any file (readme.txt with some text in it for example) inside the new disk. Then deatch the volume.

After about one or two minute, a message box would show up in Windows, saying that the device not properly removed, and the newly added disk would still show in "My Computer" window. But with "cinder list" command, we can see that the volume was successfully detached.

3) Now reattach to volume to instance, it would failed.

Libvirt log shows:
error : qemuMonitorJSONCheckError:357 : internal error unable to execute QEMU command '__com.redhat_drive_add': Duplicate ID 'drive-virtio-disk1' for drive

I googled yesterday afternoon, didn't find useful information. Would any one tell me whether Windows 2003/2008 as kvm fully virtualized guest supports disk hot plugging and removing or not? Or any possibility I have got something wrong?

Thanks for help!
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