Quote Originally Posted by CharlesA View Post
I have the same thing, but only with only 1 of my VDIs. I will see if exporting it and importing it fixes it.

EDIT: It turned out the problem was that VM didn't have "Use host I/O cache" enabled. All good now.
You saved my Evening! I have had One VM Machine which had disabled this Feature. After Enabling "Use host I/O cache" all slowness were gone! THANKS!