Working on my XenServer lab making a new blog post about Microsoft Deployment Toolkit 2010 my XenServer suddenly stopped function properly. My network interface was showing disconnected, even though I was connected! The biggest problem was that XenCenter reported NaN% of CPU and NaN% of memory making it impossible to create new VM’s.
Since I don’t have a CD-Rom on my XenServer I needed a way to install XenServer 5.5 from USB. There are many instructions out there, but they are long and complex. After some googling and forum searches I came over a blog post from The Generation V. Be aware that the USB stick has to be formatted with FAT, if not you will get a black screen with a blinking cursor. The process of creating a bootable USB stick in less than a minute. Download UNetbootin and XenServer ISO.
My intention was to reinstall the whole server, loosing my templates & VM’s. Then I discovered an install option that I have been missing. To repair a XenServer installation select Install or Upgrade XenServer host and then Refresh the existing installation. CTX120962 describes the steps.
A hint: When you have your USB Stick ready its booting staight to the menu you choose
“install” in the menu and your getting a “invalid kernel image” the current version of UNetbootin´s mboot.c32 has got errors. Try using an older Version of UNetbootin from sourceforge and your problem may be solved.