Veeam no longer installs SQLExpress during install, but rather PostgreSQL now by default. 

And if the original version installed was v10 , upgrade to v12 , is it still mssql?

Well, Veeam won't install a new DB for upgrade... yes, they keep the existing SQL install intact. 

Just also be aware of the upgrade path @CABelanger . Make sure you're at least on v10a before upgrade. See this KB for more info 

It’s also easy to migrate the configuration database to PostgreSQL if you want. And you will get more benefits from it.

https://helpcenter.veeam.com/docs/backup/hyperv/vbr_config_migrate.html?ver=120
 

So my question still valid, is Veeam enable “xp_cmdshell” when using MSSQL ?

Hi @CABelanger, to answer your question more specifically, I would say NO. I hope this answers your question?

Just in case you wish to read more: https://techdirectarchive.com/2023/11/03/how-to-verify-whether-the-xp_cmdshell-feature-is-enabled-or-disabled-in-mssql-server/