• This topic has 4 replies, 4 voices, and was last updated May 4, 2016 by Matthew C.

Upgrade ESXi hosts from 4.1 to 5.5

  • Hello,

    we have a Zerto installation between our prod site (VMware Ent. 4.1) and a DR site (also VMware 4.1).

    Now we are planning to upgrade both infrastructure to version 5.5 of vmware, is it possible to perform the upgrade without losing actual protection? How ?

    Thanks in advance,


    Hello Bruno,

    You can upgrade your ESXi Hosts and vCenter to 5.5 but there are some considerations that you’ll want to take. First, I have an article in regards to upgrading your ESXi host or putting the host into maintenance mode and how that will effect Zerto:


    Also, I’ve provided a link to our article on upgrading your vCenter. When using Zerto in your vCenter environment, if you can, it’s best to preserve the vCenter data base. Zerto works very closely with vCenter and all of the unique ID’s in the vCenter database. If the data base is created from scratch during an upgrade all of these ID’s are then changed by vCenter.


    Please note, in the second article about upgrading vCenter, if you can’t or don’t want to preserve the database there are additional instructions at the bottom of the article. These link to a secondary article¬†outlining steps you’ll need to take in regards to your Zerto environment if a new vCenter data base is being created.

    Please let us know if you have questions.

    Thank you,


    Hello Shaun,

    thanks for Your response, but let me explain in a detailed way:

    In the recovery site the vcenter will remain the same, it is a 5.5 vsphere appliance with a 4.1 esxi host, only the host will be upgraded.

    In the production site the vcenter is actually 4.1 (on windows machine with embedded sqlserver db), will be newly installed a 5.5 vsphere appliance, so we don’t want to migrate actual db, but we will start with a new db embedded in the vsphere appliance.

    Actually we have some vpg defined, 13 vm in total, and about 1TB storage replicated.

    The main goal will be to preserve the 1TB storage replicated, avoiding full resync. Is it possible?

    If I install a new Vcenter appliamce, how can I register Zerto with the new vcenter? Is it necessary to destroy all and do a new fresh install of Zerto?

    I’ve looked to the pages You’ve sent to me, but I’m not able to access to the last link because it require authentication on SalesForce…



    Hi Bruno, did you get an answer for this? we are trying to do the same, but 5.5 –> 6.0

    James – The key takeaway here is Bruno stated he was going to deploy an entirely new vCenter, with a fresh (blank) vCenter database. If you cannot preserve the vCenter database and use it on the new vCenter server, all Zerto config will have to be recreated. This means you’ll have to recreate your VPGs. Now you can use the files at the other side for “seed” disks, but each VPG will still need to do a “full-sync” in order to ensure data integrity.

    For this reason, the preferred method is to do an in place upgrade of vCenter. If that is not possible, the 2nd best method is to export the vCenter database, and import it on your new server. Preserving the vCenter database keeps the unique ID’s for the VMs unchanged, and that’s what Zerto keys in on. Lastly, if neither of those are options and you must move to a completely fresh vCenter, you’ll just have to re-setup Zerto, and let the VPG’s full-sync.

    Hope that helps.

You must be logged in to create new topics. Click here to login