A fun corner case in "streamOptimized" VMDK support:
The VMDK file header includes a version number.
Recent versions of ESXi will outright reject streamOptimized VMDKs that
do not self-report as using the "version 3" VMDK format. (Not a supported disk format (sparse VMDK version too old))
Although QEMU 2.1.0 and later can output to streamOptimized VMDK,
only in 2.5.1 and later does it produce "version 3" streamOptimized VMDKs.
Since version 1.1.2, COT has preferred QEMU 2.1.0 over vmdktool, but if QEMU > 2.1.0 but less than 2.5.1, it is producing version 1 VMDKs which are not usable with recent ESXi.
COT should therefore prefer QEMU over vmdktoolonly if QEMU version is at least 2.5.1, not 2.1.0.
A fun corner case in "streamOptimized" VMDK support:
Not a supported disk format (sparse VMDK version too old))vmdktool, but if QEMU > 2.1.0 but less than 2.5.1, it is producing version 1 VMDKs which are not usable with recent ESXi.COT should therefore prefer QEMU over
vmdktoolonly if QEMU version is at least 2.5.1, not 2.1.0.