We found that using the vSphere 4.x "Export to OVF" option would
produce a VMDK file that qemu-img could not convert to raw.
For older qemu-img the file would be converted to something that was
not all zeroes, but nevertheless was certainly not a raw disk image.
For current qemu-img, we get an "Operation not permitted" error which
is at least better than silent corruption.
Full details are in this bug report:
https://bugzilla.redhat.com/show_bug.cgi?id=548723
Note the links at the top of that bug are broken. The disk image
which failed is:
[][http://oirase.annexia.org/tmp/TestLinux-disk1.vmdk]
SHA1: 2c81bae89210b075acc51da9d025935470149d55
[][http://oirase.annexia.org/tmp/TestLinux.ovf]
SHA1: 30831689b8c6f1b1a1fcbb728769b5f71056a580
Rich.
Cause: the exported image is streamOptimized, which has the same header magic
with monolithicSparse, qemu would attempt to open it, without enough
verification. But the fields and compression are not handled at all, leading to
the conversion failure.
This will be fixed with the upcoming streamOptimized support patches.