As usual, I was working on my weekend on-call and I have had an alert. Our monitoring system has reported a message printed from the error log. I was seeing this very message I haven’t seen so far. The message Recovery::UnitInitPersistentVersionStore Failed exactly looks like the one below:
RecoveryUnit::InitPersistentVersionStore failed with db  name [master]
I was a little skeptical about this message. Hence I logged into the server for further investigation. The server was all good. Everything is green. And this message looks like For Your Information type of message to me. I have decided to do some research on this. I have found an interesting and existing thread on StackExchange for this very issue that our monitoring has reported.
This particular messages started to appear after a service or the server restarts. And, this belongs to a new feature called Accelerated Database Recovery. Based on the StackExchange thread, the MS support team said that this message shouldn’t be there and it is not harmful at all. Basically, it looks like this message starts to appear when SQL Server 2017 to SQL Server 2019 is upgraded using the In-Place upgrade method.
Yes! it is safe to ignore this message. And, at the same time, it is advisable to do side-by-side install instead of the In-Place upgrade method. In case you are interested in reading about In-Place and Side-by-Side Upgrade here is the article that you can refer too.