SUMMARY
If I have multiple disks in a VM, which one of them will be used as the boot disk in the destination?
ISSUE
The first disk (usually SCSI disk 0:0) of a VM will be used as the boot disk. Please ensure that the first disk in each VM is the boot disk otherwise deploy may fail. Note that the boot disk set by BIOS will not be used.
Secondary IDE disks can cause issues because they are placed in front of the SCSI disks. Use of IDE disks is discourage for this and performance reasons.