vSphere 5.5 – Upgrade ESXi 5.1 to ESXi 5.5

vSphere 5.5 is publicly released and it is genrally available to download for public. Ok, what would be the next step? Yes it is to evaluate the features of vSphere 5.5 by installing or Upgrading your ESXi 5.1 to ESXi 5.5. To help you on that, this post covers the step by step procedure to upgrade the ESXi 5.1 to ESXi 5.5.

You can upgrade to ESXi 5.5 hosts directly from ESXi 5.0 or ESXi 5.1 host and also in most cases you can migrate an ESX 4.x or upgrade ESXi 4.x host directly to ESXi 5.5.
The following ESX/ESXi 4.x and ESXi 5.0 versions are supported for upgrade to ESXi version 5.5:
ESX/ESXi 4.0.x (including all released updates and patches)
ESX/ESXi 4.1.x (including all released updates and patches)
ESXi 5.0.x (including all released updates and patches)
ESXi 5.1.x (including all released updates and patches)
Download the ESXi 5.5 from the VMware Website. My post related to Download vSphere 5.5 software.
1. Attach the ISO image of the ESXi 5.5 to your ESXi 5.1 if you have any remote management server tools like ILO, DRAC or insert the installation media into the server.
2. Make sure Server BIOS is configured to boot from CD-ROM
3.Once It is booted with installation media, Select  ESXi-5.5.0-1331820-standard Installer and Press Enter
4. ESXi 5.5 installer will load the Files and it may take few minutes to complete. Once it is loaded , It will Relocate the Modules and start the kernel.
5.In the Welcome Screen of VMware ESXi 5.5.0 Installation. Hit Enter to start the Installation.
6. Review the End User License Agreement and Hit F11 to Accept and continue
7. It will Scan the available devices and it may take few seconds.
8. Select the Disk to install or Upgrade ESXi 5.5 and Press Enter to continue
9.Select the Option Upgrade ESXi, Preserve VMFS datastore to upgrade to ESXi 5.5 form ESXi 5.1 by preserving the  existing VMFS datastore. Press Enter to continue.
10.Press F11 to confirm to proceed with the upgrade. This installer is configured to upgrade your system for ESXi 5.1.0 to ESXi 5.5.50 on the selected disk. It will take few minutes to complete the Upgrade Process.
10. Once Upgrade is complete. Remove the attached installation media and Press Enter to Reboot the server. you will be provided with evaluation mode for 60 days to play around with your vSphere 5.5 Features. 
Thats it. Your server is ready with ESXi 5.5. I hope this is informative for you. Thanks for Reading !!!!!