At 02/18/2011 05:09 AM, Eric Blake Write:
On 02/16/2011 08:32 PM, Wen Congyang wrote:
> Steps to reproduce this bug:
> 1. virsh attach-disk domain --source diskimage --target sdb --sourcetype file
--driver qemu --subdriver qcow2
> error: Failed to attach disk
> error: operation failed: adding
scsi-disk,bus=scsi0.0,scsi-id=1,drive=drive-scsi0-0-1,id=scsi0-0-1 device failed: Property
'scsi-disk.drive' can't find value 'drive-scsi0-0-1'
> 2. service libvirtd restart
> Stopping libvirtd daemon: [ OK ]
> Starting libvirtd daemon: [ OK ]
> 3. virsh attach-disk domain --source diskimage --target sdb --sourcetype file
--driver qemu --subdriver raw
> error: Failed to attach disk
> error: operation failed: adding lsi,id=scsi0,bus=pci.0,addr=0x6 device failed:
Duplicate ID 'scsi0' for device
>
> The reason is that we create a new scsi controller but we do not update
> /var/run/libvirt/qemu/domain.xml.
I agree that this is a bug, and that this patch is one way to solve
things; however, I'm not convinced it's necessarily the right way.
Should we be instead rolling back and undoing the new controller
creation if adding the device fails?
We use qemuDomainFindOrCreateSCSIDiskController() to create scsi disk controller,
so we do not know whether we create a new controller.
Should the successful addition of a controller save domain state at that
point, even though that means two saves instead of one if this succeeds
here?
Yes, it may be another way to solve this bug.
But, it will cause too many saves(For example, if we attach a scsi which uses scsi disk
controller 100, and we will create scsi disk controller 1 to 100)
But, if others agree with this approach, then ACK to the code.