CentOS upgrade hostname correction steps


While upgrading the Unitrends appliance Operating System from CentOS 6 (CE6) to CentOS 7 (CE 7), the requirements for naming the appliance change. In some cases, appliances with a valid hostname under CE6 to become invalid after migrating to CE7. This was commonly seen when underscores where used in the hostname but could be also by other characters as well. 


While this issue is now addressed in the current migration process, some early migrations may require these additional steps in order to update the appliance's hostname.


Post-migration, the File Level Recovery (FLR) process may fail due to inconsistencies in the hostname. 


This issue can be identified by navigating to the recover page in filter->appliance. If the CE7 hostname is listed here, this is an indication that the appliance is impacted and these steps are required to correct the issue.




Navigate to Configure > Edit appliance. Go to General and set the desired hostname (CE6 hostname or different) to name and desired FQDN.

On this page, the hostname is “vmware-ub” and FQDN is a “HOSTNAME.DOMAIN“. The FQDN is incorrectly listed as “vmware-ub.localdomain“.

Update the hostname here to make the required system changes.

After correction, the new hostname will not be observed in “Filter Backups”>” Appliance” and the FLP will work correctly.



  • After changing the hostname appliance certificate from Unitrends became invalid and needs to be updated. With the wrong certificate, an appliance can not be a backup copy target as the source check this certificate during adding the appliance as a target. The KB about certificates - User Installation of Apache SSL/TLS Certificates on a Unitrends system. This needs to be done after any hostname changes.

  • If a user tried to add an appliance after migration as a target with the wrong certificate he will get an error “Cannot change hostname of a Vault.“ - This means he has to remove the appliance from the list of appliances on “Configure“->"Appliances”, remove IP address of the target appliance from the source, fix certificates and repeat the procedure.

  • Any updates of the appliance hostname invalidate the appliance certificate.



FLR - File Level Restore

rFLR - remote File Level Restore

CE6 appliance - the appliance we migrated from.

CE7 appliance - the appliance we migrated to.

CE6 hostname - CE6 appliance hostname, the hostname of the appliance we did the migration from.

CE7 hostname - CE7 appliance hostname, the hostname of the new CE7 appliance before migration.

Souce appliance - the appliance we actually did backups and send copies to targets(it may hard drive storage, cloud storage, tape device or other appliance)

Target appliance - the appliance we use as storage that keeps backups copies. The appliance with backup copies can provide information about backups and even do FRL(it is rFLR for the source appliance).


Have more questions?

Contact us

Was this article helpful?
0 out of 0 found this helpful

Provide feedback for the Documentation team!

Browse this section