Download the latest version of Veeam Backup & Replication 9.0 ISO from: www.veeam.com/downloads.html.
Ensure that the latest run for all existing jobs has completed successfully. If some jobs have failed, re-run the failed jobs. Otherwise, job upgrade procedure may fail.
Ensure there are no running jobs, including restore sessions, Instant VM Recovery sessions and SureBackup jobs. Do not stop running jobs, let them complete successfully instead. Disable all periodic and backup copy jobs temporarily to prevent them from starting during the upgrade.
Mount the product ISO and use autorun, or run the Setup.exe file.
Click the Veeam Backup & Replication tile.
Follow the upgrade wizard steps. Be sure to select the same Microsoft SQL database and instance that was used by the previous product version.
Wait for the setup program to perform the upgrade.
Once the installation is complete, download and install the latest available update from www.veeam.com/updates.html.
Open the Veeam Backup & Replication console. If necessary, the automated upgrade wizard will be automatically launched, prompting you to upgrade product components running on remote servers. Follow the wizard to complete the upgrade process.
If some remote servers are unavailable at the time of upgrade, you can run the Upgrade wizard at any time later from the main product menu, or by closing and re-opening the Veeam Backup & Replication console. Note that out-of-date product components cannot be used by jobs until they are updated to the backup server version.
Reset CBT for all VMs in the environment. For more information, refer to the Veeam support article KB1113.
Enable all scheduled jobs that you have disabled before the upgrade.