Downgrade ESXi host from ESXi 5.5 to ESXi 5.1 Update 2

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I successfully downgrade 5.5 to 5.1 in our LAB environment using with a small work-around. The key was to to change the first line in the Manifest.txt to show a 5.1 config.

  1. use VMware vSphere CLI on your workstation and execute " --server -s \esxi.tar.gz" save the 5.5 config to a gzipped tar ball
  2. I used Winscp to upload the .tar.gz back to the ESXi server to change some files. I tried this with 7z. didn’t work. It needs linux to properly pack the files. Extract the archive with “tar zxvf esxi.tar.gz” to a temp directory
  3. edit the Manifest.txt and change the line RELEASELEVEL=VMware ESXi 5.5.0 GA to RELEASELEVEL=VMware ESXi 5.1.0 Update 2
  4. create new tar archive with “tar zcvf esxi.tgz Manifest.txt state.tgz
  5. Upload the esxi.tgz back to your workstation
  6. install a fresh ESXi5.1 (choose install instead of upgrade, but keep the local datastores if any)
  7. apply the new config to a fresh ESXi5.1 with “ --server -l esxi.tgz

I kept the physical network and storage environment unchanged while downgrading and after the configuration restore, all the settings and even registered VMs were present. ESXi Saved me a lot of reconfiguration work! What I did next is I took a same configuration from all my hosts, just in case. Do this every month and your all set

About Marco Broeken

Marco Broeken is Author of this blog and owner of vSpecialist Consulting and has 20 years experience in IT. Marco has been rewarded with the vExpert status from 2011 - 2018.


  1. Marc Papillon says:

    Thx for those great infos, I have the same HP Proliant server as in your lab and things are not going ok with esxi 5.5. Is this why you downgrade yours to 5.1 U2 ?

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