XenServer: Install new Base Version

How to install a new base version of Citrix XenServer over an existing one, whilst maintaining the existing VMs.

Prepare For Upgrade

1. Read the release and upgrade notes.
2. Check your upgrade path: that you can upgrade directly from the version you're on to the version you're planning.
3. Shutdown the VMs: log into each machine and shut id down or use XenCenter
4. Create a backup of the VM database. This will come in handy if the upgrade fails:
   xe pool-dump-database file-name=pool-dump.xml

Get the ISO

1. In an existing linux system, plug in a USB drive and find where it is mapped:
   sudo fdisk -l
   This will give a load of information but the last 'Device Boot, Start...' and an entry like /dev/sdc1
   You can double check with the command: lsblk
   Cross check with using the device's size
2. Format it
   mkdosfs -F 32 -I /dev/sd?
   e.g. mkdosfs -F 32 -I /dev/sdc1
   If you're missing the command install the required package e.g. apt-get install dosfstools (or yum install)
3. Unmap it if it's mapped:
   sudo fdisk -l
   df -h
   umount /dev/sdc?
   (add -l if its in use)
4. Down load Xenserver:
   wget [path to Xenserver iso]
5. Burn the iso to the usb:
   dd if=/path/to/the.iso of=/dev/sdb bs=1M
6. Ensure you can boot from it: sometimes the USB won't be bootable and you need to try a different USB or a different system to make it with.

Run the Upgrade

1. Boot from the USB: you may need to use a screen and keyboard to select the USB as the boot.
2. Follow the prompts and select 'upgrade'.

Post Upgrade Tasks

1. Update Citrix XenCentre on any Windows desktops by browsing to the server's IP to get the installer.
2. Update XenServer tools on and client VMs (see Linux instruction here)
3. Check the ISO repository or any other attached storage: it likely have become detached.