vSphere 5: Software iSCSI causes ESXi boot delay
This is due to the cause of each portal will try to connect to the target up to 9 times if it failed to connect, with more portal and more targets, this can result in a long delay.
Update: The patch for this issue has been release and a new ESXi 5.0 image is also available. Please note when downloading you are provided with two different ESXi 5.0 images. My recommendation is to use the latest though I do not know the reason behind why the previous is still available.