I just upgraded Veeam ONE from 7 to v8. The upgrade is as easy as it is known from Veeam.
There is only one scenario you should take care of: if your Veeam ONE 7 SQL database has grown over 10 GB.
During installation a procedure is triggered that rebuilds indexes in the database. They do this to boost the report generation performance and other database queries.
But if your database is larger than 10 GB, this procedure needs a lot of time to complete. In this case you will see this window for a longer time:
Installing Veeam ONE Monitor Server…
Veeam has published a Knowledge Base article (KB 1951) describing what you can do if your Veeam ONE SQL database is larger than 10 GB:
If you start the upgrade without reading/taking into account the KB article, do not panic.
The time required for the script to complete depends on the database size.
All you need is time – when the rebuild of indexes is finished, you can proceed with the upgrade to Veeam ONE v8.