We ran into a problem with Update Manager on vSphere 5.1 lately:
Cannot create a ramdisk of size 329MB to store
the upgrade image. Check if the host has
The help provided in vSphere documentation says
Yeah, thanks 😀 That what the error message said in the first place 😀 But it might as well describe your exact problem, so please check http://virtualdiscussion.wordpress.com/2012/12/13/uprade-of-esxi-host-fails-using-update-manager-fails-vum/ for a possible resolution.
Well, didn’t do it for us. We had enough space … Hmmm … after a while of struggling, it turned out to be lock down mode which caused the error! After disabling it (via DCUI, as vCenter failed with a different error message) VUM remediated the host like a charm 🙂 WTF!?
So far, it didnt reproduce on any other host but let’s see what happens in the future 😉