host info:
# uname -r && rpm -q qemu-kvm
3.10.0-3.el7.x86_64
qemu-kvm-1.5.2-4.el7.x86_64

e.g:...-drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,bus=pci.0,addr=0x7,drive=drive-data-disk,id=data-disk
qemu-kvm: -drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop: 'vmdk' invalid format
/etc/qemu-ifdown: could not launch network script

Part with mentioned error was rewritten, can you please retest the bz and test the error message state?

(In reply to Miroslav Rezanina from comment #2)
> Part with mentioned error was rewritten, can you please retest the bz and
> test the error message state?
Retried it with the latest qemu-kvm version that it will give a message prompt "vmdk: Operation not supported". But still not as expected, you should refer to bug 999788#c7 that should give message prompt like: vmdk' can be only used as read-only device.

host info:
3.10.0-41.el7.x86_64
qemu-kvm-1.5.3-13.el7.x86_64

e.g:...-drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,bus=pci.0,addr=0x7,drive=drive-data-disk,id=data-disk -vnc :1 -monitor stdio
qemu-kvm: -drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop: could not open disk image /home/vmdk-data-disk.vmdk: Operation not supported

Best Regards,
sluo

Upstream 2.0 has the following message:

qemu-system-x86_64: -drive file=/stor/image/turnkey-moinmoin-12.0-squeeze-x86.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop: could not open disk image /stor/image/turnkey-moinmoin-12.0-squeeze-x86.vmdk: Driver 'vmdk' can only be used for read-only devices

Moving to POST and waiting for rebase.

Fix included in qemu-kvm-1.5.3-67.el7

Verify this issue on qemu-kvm-rhev-2.1.2-5.el7.x86_64 and qemu-kvm-1.5.3-75.el7.x86_64.

host info:
# uname -r && rpm -q qemu-kvm-rhev
3.10.0-191.el7.x86_64
qemu-kvm-rhev-2.1.2-5.el7.x86_64

e.g:...-drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,bus=pci.0,addr=0x7,drive=drive-data-disk,id=data-disk
Warning: option deprecated, use lost_tick_policy property of kvm-pit instead.
qemu-kvm: -drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop: could not open disk image /home/vmdk-data-disk.vmdk: Driver 'vmdk' can only be used for read-only devices

###################################################

host info:
# uname -r && rpm -q qemu-kvm
3.10.0-191.el7.x86_64
qemu-kvm-1.5.3-75.el7.x86_64

e.g:...-drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,bus=pci.0,addr=0x7,drive=drive-data-disk,id=data-disk
Warning: option deprecated, use lost_tick_policy property of kvm-pit instead.
qemu-kvm: -drive file=/home/vmdk-data-disk.vmdk,if=none,id=drive-data-disk,format=vmdk,cache=none,werror=stop,rerror=stop: could not open disk image /home/vmdk-data-disk.vmdk: Driver 'vmdk' can only be used for read-only devices

Best Regards,
sluo

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2015-0349.html