Hosts might contain third-party software, such as Cisco Nexus 1000V VEMs or EMC PowerPath modules. To upgrade or migrate such hosts successfully, you must either use a custom ESXi image or delete the third-party modules during remediation.

You cannot directly migrate third-party solutions as part of a host upgrade. Architectural changes between ESX/ESXi 4.x and ESXi 5.x and VIB forward incompatibility result in the loss of third-party components and possible system instability. To accomplish such migrations, you can create a custom ISO file with ESXi Image Builder CLI. For information about upgrading with third-party customizations, see the vSphere Upgrade documentation. For information about using ESXi Image Builder CLI to make a custom ISO, see the vSphere Installation and Setup documentation.

You can remove installed third-party solutions by using the Update Manager Remediate wizard.

ESXi 5.0, ESXi 5.1 hosts and ESXi 5.5 hosts are binary compatible. Any third-party software modules on ESXi 5.0 and ESXi 5.1 hosts will remain intact after upgrade to ESXi 5.5, regardless of whether you chose to remove third-party modules.

If you are upgrading an ESXi 5.0 or ESXi 5.1 host to ESXi 5.5 host, supported custom VIBs on the host that are not included in the ESXi installer ISO are migrated. If the host or the upgrade ISO image contains a VIB that creates a conflict and prevents the upgrade, an error message identifies the conflicting VIB. You can remove the VIB and retry the upgrade, or use ESXi Image Builder CLI to create a custom .iso that resolves the conflict.

To discover potential problems with third-party software before an upgrade or migration operation, scan the hosts against an upgrade baseline and review the scan messages in the Update Manager Compliance view. See Host Upgrade Scan Messages in Update Manager and Host Upgrade Scan Messages When Cisco Nexus 1000V Is Present.